GAS  TORCH 

AND 

THERMIT  WELDING 


°Ms  QrawMlBook  &  7ne 


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GAS  TORCH 

AND 

THERMIT  WELDING 


BY  V.-A:' 

ETHAN  VIALL 

EDITOR  AMERICAN  MACHINIST 

Member  American  Society  of  Mechanical  Engineers,  Society  of  Automotive  Engineers, 

American  Institute  of  Electrical  Engineers,  Franklin  Institute,  American  Welding 

Society.    Author  of  Manufacture  of  Artillery  Ammunition,  United  States 

Artillery  Ammunition,   United  States  Rifles  and  Machine  Guns, 

Broaches  and  Broaching,  and  Electric  Welding. 


FIRST  EDITION 


McGRAW-HILL  BOOK  COMPANY,  INC. 

NEW  YORK:   370    SEVENTH  AVENUE 

LONDON:  6  &  8  BOUVERIE  ST.,  E.  C.  4 

1921 


COPYRIGHT,  1921,  BY  THE 
McGRAW-HILL  BOOK  COMPANY,  INC. 


PREFACE 

THE  beginner,  the  practical  worker,  the  student  and  the 
engineer,  will  find  in  this  book  a  great  amount  of  information 
regarding  gas-torch  and  Thermit  welding  practice  and  equip- 
ment. No  toil  or  expense  has  been  spared  to  gather  material  of 
real  and  lasting  value.  Shops  have  been  visited  and  data  and 
photographs  obtained  first  hand.  Practically  every  book  on 
welding  has  been  carefully  scrutinized  for  helpful  suggestions. 
The  services  of  experts  have  been  engaged  to  give  the  results  of 
long  practice  and  research  in  their  special  lines.  Each  and 
every  plan  known  to  the  experienced  editor  has  been  employed 
to  give  the  reader  the  highest  possible  grade  of  information. 

The  historical  references  have  been  cut  to  the  barest  state- 
ment of  facts  as  we  have  been  able  to  obtain  them,  yet  they  are 
ample  enough  to  give  the  inquiring  mind  the  genesis  of  each 
class.  Foreign  methods  and  equipment  have  not  been  touched 
upon,  except  in  a  few  instances,  because  such  treatment  would 
add  too  greatly  to  the  bulk  of  this  work,  without  adding  an 
appreciable  amount  to  its  real  value,  since  the  methods  and 
standard  equipment  here  are,  in  general,  far  in  advance  of 
anything  similar  elsewhere. 

Great  care  has  been  taken  to  indicate  the  sources  of  informa- 
tion and  to  give  the  names  and  addresses  of  the  makers  of  equip- 
ment shown.  It  is  believed  that  every  well  known  maker  of  this 
class  of  welding  apparatus  in  the  United  States  has  been  men- 
tioned at  least  once  in  these  pages.  This  has  not  been  done 
with  any  idea  of  advertising  them,  but  because  it  is  information 
every  reader  is  entitled  to  have  without  the  necessity  of  making 
a  separate  search  for  it. 

Of  course  no  recommendations  regarding  the  best  apparatus 
to  use  are  made  in  any  case.  As  in  any  other  line,  improvements 
are  being  constantly  made,  but  in  regard  to  newly  invented  or 
unknown  equipment  the  seller  should  be  made  to  prove  his  case 
before  an  investment  is  made.  Apparatus  which  does  not  meet 

v 

447791 


vi  PREFACE 

the  present  day  requirements,  soon  drops  out  of  sight.  It  is  a 
good  plan  for  a  prospective  purchaser  of  equipment  to  consult 
some  well  established  firm  which  is  not  afraid  to  advertise  its 
product  in  open  competition.  Such  a  firm  will  see  that  its 
equipment  is  properly  installed  and  works  satisfactorily. 

ETHAN  VIALL. 
New  York  City, 
November,  1920. 


*    V 


TABLE  OF  CONTENTS 
PART  I— GAS  TORCH  WELDING. 

CHAPTER  I 

PAGE 

HISTORY  AND  USES  OF  THE  GAS  TORCH , . . . .       1-    8 

Meaning  of  " Autogenous ' 7  and  the  Term  "Gas  Torch" 
Welds — The  Oxy-Acetylene  Gas  Torch — Used  for  Both  Weld- 
ing and  Cutting — Hydrogen  Gas — Thermalene  Gas — Blaugas — 
Drigas — Illuminating  Gas — Benzine  or  Benzol  Vapors — Ex- 
plosive Limits  of  Welding  Gases — The  Field  of  Gas  Torch 
Welding  and  Cutting. 

CHAPTER  II 

THE  PRODUCTION  OF  WELDING  GASES — OXYGEN  AND  HYDROGEN  ....  9-25 
Oxygen  by  the  Liquid  Air  Process — Oxygen  and  Hydrogen  by 
the  Electrolytic  Method — General  Principles  of  the  Elec- 
trolytic Method — Details  of  the  Davis-Bournonville  Electrolyzer 
Cell — The  International  Oxy-Hydrogen  Generator — The  Levin 
Type  of  Generator. 

CHAPTER  III 

ACETYLENE  AND  MEDIUM,  OR  POSITIVE,  PRESSURE  GENERATORS  ....  26-  40 
Acetylene — Acetylene  Cylinders — Acetone  Injurious  to  a 
Weld — Estimating  Amount  of  Acetylene — Types  of  Acetylene 
Generators — The  Positive  Pressure  Generator — The  Davis- 
Bournonville  Types — The  Buckeye  Carbide-Feeding  Mechan- 
ism— The  Portable  Pressure  Type — Approximate  Dimensions 
and  Weights  of  Acetylene  Generator  Sets. 

CHAPTER  IV 

Low  PRESSURE  ACETYLENE  AND  THERMALENE  GENERATORS 41-  53 

Low  Pressure  Generators — The  Oxweld  Duplex  Generators — 
Thermalene  Generators — How  the  Cartridge  is  Packed — Action 
of  the  Thermalene  Generator — Some  Advantages  of  Thermalene, 

vii 


viii  CONTENTS 

CHAPTER  V 

PAGE 

GAS  TORCHES  USED  FOR  WELDING 54-  73 

Types  of  Torches — The  Davis-Bournonville  Positive  Pressure 
Torch — The  Prest-O-Lite  Torch — The  General  Welding  Co.'s 
Torch — The  Imperial  Torches — Calculating  Amount  of  Gas 
Used — The  Eego  Welding  Torch — The  Oxweld  Low  Pressure 
Torch — The  Messer  Torch — The  Thermalene  Torch. 

CHAPTER  VI 

GAS  CUTTING  TORCHES , 74-  94 

The  Davis-Bournonville  Cutting  Torch — The  Oxweld  Cutting 
Torch — Cutting  Data — The  Messer  Torch — The  General 
Welding  Co. 's  Torch — Imperial  Torches — Carbo-Hydrogen 
Torches — Airco-Vulcan  Combination  Torch — The  Rego  Torch — 
The  Milburn  Combination  Torch — The  Torchweld  Torch — The 
Davis-Bournonville  Underwater  Cutting  Torch. 

CHAPTER  VII 

GAS-PRESSURE  REGULATORS  AND  WORKING  ASSEMBLIES 95-115 

Oxweld  Oxygen  Regulators  and  Gages — Other  Regulators  and 
Gages — Tank  and  Hose  Colors — Regulator  Adaptors — Con- 
necting Up  an  Outfit^The  Two  Types  of  Tank  Connec- 
tions— Characteristics  of  the  Oxy-Acetylene  Welding  Flame — 
Imperial  Three-Way  Outfit — Lighting  the  Oxweld  Low  Pres- 
sure Torch — Characteristics  of  the  Oxy-Hydrogen  Flame — 
Characteristics  of  the  Hydrogen-Compressed  Air  Flame — Char- 
acteristics of  the  Oxy-Illuminating  Gas  Flame. 

CHAPTER  VIII 

GAS  TORCH  WELDING  AND  CUTTING  OUTFITS 116-130 

Typical  Oxy-Acetylene  Cutting  Unit — Manifolds — Complete 
Working  Outfits — Back  Pressure  Valves — Lead  Burning — 
Method  of  Connecting  Outfits  for  Various  Gas  Combinations — 
A  Gas  Flow  Indicator. 

CHAPTER  IX 

LEARNING  TO  WELD  WITH  THE  GAS  TORCH 131-153 

The  Way  to  Hold  a  Torch — Torch  Motion — Welding  Two 
Plates — Allowing  for  Seam  Contraction — Using  the  Welding 
Rod — Various  Welding  Jobs — Sources  of  Trouble — Built-Up 
Welds — Vertical  Welds — Filling  Up  a  Hole — Forming  Bosses 
or  "Putting  on"  Metal — Practicing  on  Gear  Teeth — Welding 
Backward — Lead  Burning. 


CONTENTS  IX 

CHAPTER  X 

PAGE 

MAKING  ALLOWANCE  FOR  EXPANSION  AND  CONTRACTION 154-168 

Action  of  Metal  When  Heated — Using  Heating  Torches — 
Cooling  Work — The  Wiederwax  Preheater — Suggestions  Re- 
garding the  Welding  of  Gratings  and  Pulleys — Automobile 
Cylinder  Work. 

CHAPTER  XI 

WELDING  VARIOUS  METALS  AND  THE  FLUXES  USED 169-186 

Properties  of  Metals — Conductivity  and  Oxidation — Vaporiza- 
tion of  Substances — Separation  of  Elements — Welding  Various 
Metals — Welding  Aluminum — Filling  a  Large  Hole — Brass 
and  Bronze — Cast  Iron — Cast  Iron  to  Steel — Copper — Copper 
to  Steel — Lead — Malleable  Iron — Monel  Metal — Nickel — 
Steel — Special  Steels — Manganese  Steel — Nickel  Steel — Vana- 
dium Steel — Chrome  Steel — Wrought  Iron — Galvanized  Iron — 
German  Silver — White  Metal  Castings — Silver — Gold. 

CHAPTER  XII 

EXAMPLES  OF  WELDING   JOBS  . . . 187-220 

Preparing  for  Welding — Examples  of  Special  Jobs — Welding 
Broken  Machine  Tools — Preparation  for  Locomotive  Frame 
Welding — Cooling  Devices — Rail  Bonding — Rudder  Frame 
Welding — Large  Engine  Cylinder  Work — Welding  High  Speed 
Steel  Tips  to  Low  Carbon  Shanks  for  Shop  Tools. 

CHAPTER  XIII 

WELDING  JIGS  AND  FIXTURES 221-238 

Holding  Pipe  for  Welding — A  Welding  Table — V-Blocks  for 
Holding  Shafts — Jig  for  Holding  Crankshafts — An  Adjust- 
able Crankshaft  Jig — Crankcase  Devices — Motorcycle  Mani- 
fold Jig — Sheet  Metal  Roller  Jig — Sheet  Metal  Cylinder 
Jig — Apparatus  for 'Welding  Cylinder  Ends — Welding  Poison 
Gas  Containers — Liberty  Motor  Work — Fixtures  for  Motor 
Manifolds. 

CHAPTER  XIV 

WELDING  MACHINES 239-256 

The  Duograph — How  the  Duograph  Works — Drum  Welding 
Machine — Light  Seam  Welding  Machine — Machine  for  Weld- 
ing Oblong  Seams — Tube  Welding  Machines — Tube  Welding 
by  the  Oxy-Acetylene  Process — Arrangement  of  Rolls  on  a 
Tube  Welding  Machine. 


X  CONTENTS 

CHAPTER  XV 

PAGE 

CUTTING  WITH  THE  GAS  TORCH 257-277 

Correct  Cutting  Position — Starting  a  Cut — Examples  of  Good 
and  Bad  Work — Blowing  a  Hole  Through  a  Plate — Using 
Various  Devices — Flame  Control — Making  a  Ladle  Hook — - 
Costs  of  Some  Cutting  Jobs — Cutting  Cast  Iron— Torches 
Made  to  Preheat  the  Oxygen — Cost  of  Oxy-Hydrogen  Cutting. 

CHAPTER  XVI 
CUTTING  MACHINES 278-294 

Cutting  with  Hand  Machines — The  Radiagraph — The  Railo- 
graph — Circular  Cutting — The  Magnetograph — The  Camo- 
graph— The  Great  Western  Cutter — The  Pyrograph — The  Uni- 
versal Cutter — The  Oxygraph. 

CHAPTER  XVII 

WELDING  SHOP  LAYOUT,  EQUIPMENT  AND  WORK  COSTS 295-313 

The  Equipment  Necessary  for  a  First  Class  Shop — Layout  of 
the  Oxweld  Shop — Keeping  Track  of  Costs — The  Oxweld  Cost 
Form — The  Imperial  Cost  Form — Carbon  Burning — Safety 
Rules  for  Gas  Torch  Workers — U.  S.  Railway  Administration 
Autogenous  Welding  Rules — Strength  of  Oxy-Acetylene  Welds. 

PART  II— THERMIT  WELDING. 
CHAPTER  I 

THERMIT  WELDING:  ITS  HISTORY,  NATURE  AND  USES 317-321 

What  Thermit  Is — Temperature  and  Characteristics— Plastic 
and  Fusion  Methods — Kinds  of  Thermit  Commonly  Used — 
Plain  Thermit — Railroad  Thermit — Cast  Iron  Thermit. 

CHAPTER  II 

MAKING  PLASTIC  PROCESS  WELDS 322-332 

Uses  of  the  Three  Varieties  of  Thermit — A  Pipe  Welding  Out- 
fit— How  the  Mold  is  Used — Placing  and  Igniting  Thermit — 
Removing  the  Mold — Cost  and  Strength  of  Pipe  Welds. 

CHAPTER  III 

FUSION  WELDING  OF  HEAVY  SECTIONS 333-357 

Type  of  Crucible  Used  for  Thermit  Welding — Tapping  a 
Crucible — Life  of  Lining  Prolonged  With  Magnesia  Tar — 
Crucible  Ready  for  Baking — Thimbles — Application  of  Fusion 
Welding — Wax  Pattern  Molds — Ramming  the  Mold — Preheat- 
ing the  Mold — Igniting  Thermit — Amount  of  Thermit  Needed 
for  Welds — Locomotive  Frame  Work, — Other  Railroad  Work, 


CONTENTS  xi 

CHAPTER  IV 

PAGE 

WELDING  CRANKSHAFTS,  MILL  PINION  TEETH,  ETC 358-373 

V-Blocks  for  Welding  Crankshafts — Defects  that  Frequently 
Occur — Inaccuracy  of  Alignment  Explained — How  to  Locate 
Minute  Cracks — Welding  New  Teeth  in  Large  Pinions — Mak- 
ing a  Wax  Tooth  Pattern — Another  Method  of  Welding  Pinion 
Teeth — Preheating  Large  Work. 

CHAPTER  V 

WELDING  NEW  NECKS  ON  LARGE  PINIONS  AND  OTHER  HEAVY  WORK  374-390 
Two  Methods  of  Working — Foundation  and  Heating  Arrange- 
ments— Constructing  the  Mold  for  a  Large  Roll  or  Pinion — 
Amount    of    Thermit   Required — Treatment    When   a   Cope    is 
Used — Alternate  Method — Marine  Repairs. 

CHAPTER  VI 

RAIL  WELDING  FOR  ELECTRIC  SYSTEMS 391-402 

Rail  Joint  Work — Adjusting  the  Insert  Between  the  Rails — 
Adjusting  the  Mold — Preheating — The  llse  of  Thermit  Addi- 
tions— The  Grinding  Machine-. 

CHAPTER  VII 

WELDING  COMPROMISE  RAIL  JOINTS 403-412 

Kinds  of  Compromise  Joints — Using  a  Rail  Section  for  a  Pat- 
tern— The  Clark  Joint — Modified  Clark  Joint — Welded  Cross- 
over— Motor  Case  Work — Car  Truck  Work. 

CHAPTER  VIII 

WELDING  CAST  IRON  AND  OTHER  PARTS 413-425 

Thermit  to  Use  for  Cast  Iron — Examples  of  Cast  Iron  Welds — 
Welding  High  Speed  to  Machinery  Steel — Cost  of  Thermit  Ap- 
paratus— Preheaters  for  Thermit  Work — Cost  of  Materials  and 
Apparatus  for  Pipe  Work. 

INDEX   . 426 


PART  1-GAS  TORCH  WELDING 


GAS  TOUCH  AND  THEKMIT  WELDING 


CHAPTER  I 
HISTORY  AND  USES  OF  THE  GAS  TORCH. 

According  to  common  usage,  the  term  * '  autogenous  weld- 
ing" is  erroneously  applied  only  to  hot  gas  flame  fusion  welds. 
The  gas  combinations  used  for  the  production  of  the  hot  flame 
for  welding  or  cutting  are  oxy-acetylene,  oxy-hydrogen,  oxy- 
thermalene  or  any  combination  that  will  produce  sufficient  heat, 
and  is  applied  by  means  of  a  torch  or  blow-pipe.  The  welds  so 
produced  are  strictly  fusion  welds,  as  no  pressure  or  ham- 
mering is  employed  to  effect  the  union.  The  word  ' '  autogenous ' '' 
means  "self -produced"  or  "  self  -generated,"  that  is,  joined  with 
the  same  metal,  and  as  such  applies  equally  to  hot  gas  flame, 
electric  arc  or  thermit  welds,  although  as  just  stated,  the  present 
custom  is  to  apply  the  term  generally  to  hot  gas  flame  welds. 
However,  owing  to  the  wide  field  that  the  term  "autogenous" 
really  covers,  and  to  the  looseness  with  which  it  is  often  applied, 
we  prefer  to  use  the  term  "gas  torch"  in  connection  witji 
welding  and  cutting  by  means  of  the  hot  gas  flame. 

While  the  use  of  a  blow-pipe  or  torch  in  some  form  was 
known  to  the  ancients,  the  high  temperature  gas  flame  is  & 
development  of  the  last  quarter  of  a  century.  The  more  com- 
monly known  gas  combination  is  oxy-acetylene.  Acetlyene 
(C2H2)  was  discovered  by  Edmund  Davy  in  1836,  but  it  re- 
mained only  a  laboratory  gas  until  T.  L.  Willson  of  North 
Carolina  and  H.  Moisson,  the  Frenchman,  developed  commercial 


^  TORCH  AND  THERMIT  WELDING 

methods  of  producing  calcium  carbide  (CaC2)  in  large  quanti- 
ties in  1891-92.  In  1895  Le  Chatelier  read  a  paper  before  the 
Paris  Academy  of  Sciences  in  which  he  stated  that :  * '  acetylene 
burned  with  an  equal  volume  of  oxygen  gives  a  temperature 
which  is  1000  deg.  C.  (1800  deg.  F.)  higher  than  the  oxy- 
hydrogen  flame.  The  products  of  the  combustion  are  carbon 
monoxide  and  hydrogen,  which  are  reducing  agents."  Further 
along  he  said:  ''this  double  property  makes  the  use  of  acety- 
lene in  blow-pipes  of  very  great  value  for  the  production  of 
high  temperatures  in  the  laboratory. ' '  This  statement  of  Le 
Chatelier  is  especially  noteworthy,  since  he  set  the  ratio  of  the 
gases  at  equal  volumes,  and  not  at  the  theoretical  proportion 
of  2J  volumes  of  oxygen  to  1  of  acetylene. 

The  application  of  the  oxy-acetylene  gas  torch  to  metallic 
welding  dates  experimentally  from  1901,  and  industrially  from 
1903.  Edmond  Fouche,  of  Paris,  who  did  considerable  experi- 
menting in  conjunction  with  Pi  card,  is  generally  credited  with 
having  devised  the  first  really  practical  and  safe  torch.  In 
February  1904  Fouche  sent  two  of  his  torches  to  Eugene 
Bournonville,  of  New  York,  with  which  the  latter  repaired  a 
machine  that  was  still  in  use  years  later.  The  Fouche  and 
Picard  torch  first  developed,  used  both  oxygen  and  acetylene 
under  high  pressure.  There  proved  to  be  serious  objections  to 
this,  and  Fouche  next  produced  the  low  pressure  or  injector 
type  of  torch  which  employed  only  the  oxygen  under  high  pres- 
sure. Following  these  was  the  Gauthier-Ely  positive  pressure  or 
medium-pressure  type  which  used  both  gases  under  moderate 
and  independent  pressures.  This  type  was  later  brought  to 
the  United  States  by  Augustine  Davis  and  Eugene  Bournon- 
ville in  1906.  During  this  year  Bournonville  designed  the  first 
acetylene  pressure  generator  produced  in  connection  with  the 
oxy-acetylene  process. 

In  1905  and  1906  considerable  welding  work  was  done  but 
the  process  was  handicapped  by  the  inadequacy  and  poor 
quality  of  the  oxygen  then  obtainable,  and  also  by  the  im- 
perfect knowledge  and  technique  necessary  to  good  work.  In 
1902,  Carl  Linde  patented  in  England  a  process  for  liquefying 
air  and  producing  oxygen  and  nitrogen.  In  1906  a  plant  for 
the  production  of  oxygen  by  the  Linde  process  was  established 
in  Buffalo,  N.  Y.  From  that  time  on,  oxygen  plants  of  various 


HISTORY  AND   USES  OF  THE   GAS  TORCH  3 

kinds  have  constantly  increased  in  number  and  the  commercial 
production  of  oxygen  of  good  quality  has  been  a  great  factor 
in  the  development  of  gas  torch  welding. 

At  first,  operations  were  limited  to  the  simplest  repair  work 
on  iron  or  steel.  As  the  apparatus  was  improved  and  the 
efficiency  of  the  welders  increased,  the  field  widened.  New 
uses  have  been  found  for  the  process  and  the  range  of  metals 
coming  within  its  scope  has  steadily  expanded.  It  has  its 
limitations,  however,  which  will  be  pointed  out  elsewhere. 

Used  for  Both  Welding  and  Cutting.— In  addition  to  weld- 
ing, the  oxy-acetylene  flame,  as  well  as  a  number  of  others, 
is  applicable  to  cutting.  In  fact  so  closely  allied  are  welding 
and  cutting  in  this  field,  that  an  operator  is  usually  called 
upon  to  do  both  many  times  in  a  day's  work.  Cutting  by 
means  of  an  oxygen  jet  was  first  made  commercially  possible 
by  Jottrand,  who  took  his  basic  patent  in  1905. 

Aside  from  the  manual  operation  of  welding  or  cutting 
torches,  a  large  number  of  machines  have  been  designed.  These 
range  from  simple  wheel  or  radius  attachments  for  the  torch 
itself,  to  huge  automatic  pipe  making  machines  or  others  of  a 
complicated  nature. 

The  oxy-acetylene  flame  consists  of  two  parts,  a  small  inner 
luminous  "cone"  which  is  bluish  white  in  color,  and  a  larger 
enveloping  non-luminous  flame.  The  temperature  at  the  apex 
of  the  cone  is  estimated  to  be  about  6300  deg.  F.  This  heat  is 
not  surpassed  by  any  burning  gas  with  the  possible  exception 
of  thermalene,  for  which  6500  deg.  F.  is  claimed. 

For  welding  purposes  the  high  efficiency  of  acetylene  is  due 
to  its  high  carbon  content  and  to  the  fact  that  it  is  endothermic, 
that  is  to  say,  heat-absorbing  in  its  formation.  Energy 
stored  up  in  formation  is  given  off  again  in  the  form  of 
heat  by  the  acetylene  upon  dissociation.  It  is  calculated  that 
of  1475  heat  units  in  a  cubic  foot,  227  are  due  to  the  mere 
breaking  up  of  the  gas.  While  theoretically  two  and  one-half 
volumes  of  oxygen  are  needed  to  completely  burn  one  volume  of 
acetylene,  the  ratio  in  which  the  gases  are  employed  in  prac- 
tice is  about  one  volume  of  oxygen  to  one  volume  of  acetylene. 
The  flame  yielded  by  such  a  mixture  is  the  correct  one,  or  the 
so-called  "neutral"  flame.  By  increasing  or  decreasing  the 
proportion  of  oxygen,  flames  known  as  either  oxidizing  or 


4  GAS  TORCH  AND  THERMIT  WELDING 

reducing  may  be  obtained,  the  appearance  of  the  cone  changing 
as  the  proportions  are  modified. 

While  the  use  of  oxy-acetylene  for  welding  is  more  commonly 
known  than  any  other  combination,  there  are  several  gases,  which 
when  mixed  with  oxygen,  will  produce  more  or  less  satisfactory 
welds.  Some  cf  them  are  to  be  preferred  to  acetylene  for 
certain  cutting  purposes.  The  better  known  gases  are  described 
as  follows,  it  being  understood  that  they  are  to  be  used  with 
oxygen. 

Hydrogen  gas  is  a  chemical  element  which  exists  in  nature 
in  great  quantities  in  various  chemical  combinations.  The  most 
common  is  its  union  with  oxygen  to  form  water  (H20).  As  a 
consequence,  water  is  used  as  a  basis  for  making  both  oxygen 
and  hydrogen.  Oxy-hydrogen  welding  was  the  first  gas  torch 
welding  system  employed,  and  it  was  used  quite  extensively 
until  the  introduction  of  the  more  advantageous  system  of  weld- 
ing with  oxy-acetylene.  While  hydrogen  may  be  manufactured 
on  the  premises,  it  is  also  handled  commercially  in  steel  cylinders» 
In  using  this  flame  for  welding  there  is  an  existing  danger  that 
the  oxygen  may  unite  with  the  metal  causing  it  to  be  overheated 
or  burnt.  To  prevent  the  burning  of  the  metal,  it  becomes 
necessary  to  use  a  supercharge  of  hydrogen  so  that  oxygen 
liberated  within  the  flame  will  combine  with  the  free  hydrogen 
instead  of  with  the  metal.  This,  however,  increases  the  size 
and  decreases  the  temperature  of  the  flame.  The  temperature 
of  the  oxy-hydrogen  flame  according  to  Kautny,  can  never  go 
higher  than  the  dissociation  temperature  of  water,  which  is 
estimated  at  2000  deg.  C.  (3632  F.)  For  welding  thin  metal 
sheets  hydrogen  is  practical  on  account  of  its  comparatively 
low  heat.  The  quality  of  the  weld,  however,  decreases  as  the 
thickness  of  the  metal  increases.  While  theoretically  only  two 
volumes  of  hydrogen  are  required  to  one  of  oxygen,  in  actual 
practice  when  employing  an  oxy-hydrogen  torch,  it  is  necessary 
to  use  four  or  five  volumes  of  hydrogen  to  one  of  oxygen  in 
order  to  insure  a  non-oxidizing  flame.  This  in  itself  is  a  waste- 
ful process,  since  the  maximum  heat  obtained  is  limited  to  the 
amount  produced  by  combining  two  volumes  of  hydrogen  to  one 
of  oxygen.  For  heavy  cutting  it  is  preferred  to  acetylene  on 
account  of  its  longer  flama  It  is  also  used  extensively  for  lead 

T 


HISTORY   AND   USES  OF  THE   GAS   TORCH  5 

burning,  preheating,  soldering,  brazing,  annealing,  special  forg- 
ing or  rivet  heating  and  a  number  of  other  things. 

Thermalene  is  one  of  the  latest  gases  to  be  produced.  It  is 
the  discovery  of  Linus  Wolf,  Zurich,  Switzerland,  and  it  is 
handled  in  this  country  by  the  Thermalene  Co.,  Chicago  Heights, 
111.  It  is  a  combination  produced  by  the  decomposition  of 
calcium  carbide  and  hydrocarbon  oils,  the  heat  generated  by 
the  carbide  being  used  to  vaporize  the  oil.  It  is  used  for  either 
welding  or  cutting. 

Blaugas  is  a  liquid  under  pressure.  It  is  the  discovery  of 
Herman  Blau  and  it  is  made  from  gas  oil,  a  product  of  the 
oil  refineries.  It  probably  has  the  lowest  explosive  range  of 
any  gas  used  for  illuminating  purposes,  the  range  being  about 
4  per  cent  while  that  of  coal  -gas  is  about  13  per  cent.  Like 
coal  gas,  however,  it  is  little  used  for  welding,  though  sometimes 
used  for  cutting.  Blaugas  is  marketed  in  steel  cylinders  having 
the  equivalent  of  1300  cu.ft.  of  city  gas,  by  the  American 
Blaugas  Corp.,  New  York.  Its  largest  field  is  for  cooking  and 
lighting  purposes  where  coal  gas  is  not  readily  obtainable. 
Owing  to  its  portability  it  may  be  used  to  advantage  for  pre- 
heating work. 

Drigas  is  a  light  oil  gas,  which  is  a  vapor  under  pressure. 
It  is  sold  in  steel  cylinders  of  about  150  cu.ft.  by  the  same 
concern  handling  blaugas.  It  is  especially  good  in  combination 
with  oxygen  for  cutting  metal  from  1  to  12  in.  thick,  and  is 
also  considerably  used  for  preheating.  Its  explosive  range  is 
about  ^  that  of  coal  gas,  and  it  is  non-poisonous  and  non- 
asphyxiating. 

Illuminating  Gas  (coal  gas  or  water  gas)  can  only  be  used 
for  welding  very  thin  pieces  owing  to  the  low  temperature  of 
the  flame.  It  may,  however,  be  used  for  preheating  or  cutting. 

Benzine  or  Benzol  Vapors  have  the  same  properties,  approxi- 
mately, as  blaugas.  The  temperature  is  a  little  higher  than 
that  of  illuminating  gas,  but  much  lower  than  acetylene.  It 
is  only  used  for  welding  under  special  circumstances. 

While  a  number  of  gases,  which  are  used  with  oxygen,  have 
been  mentioned,  only  the  production  and  use  of  hydrogen, 
acetylene  and  thermalene  will  be  described,  along  with  that  of 
oxygen. 

Explosive  Limits  of  Welding  Gases. — In  order  to  be  ex- 


6  GAS  TORCH  AND  THERMIT  WELDING 

plosive,  a  combustible  gas  or  vapor  must  be  mixed  with  a 
certain  amount  of  oxygen  or  air,  the  proportions  of  the  mix- 
ture ranging  between  certain  limits  depending  on  the  char- 
acter of  the  fuel.  Any  figures  showing  these  explosive  limits 
of  the  gases  can  only  be  approximate  at  best,  since  so  many 
things  enter  into  the  calculations,  such  as  the  purity  of  the 
gas,  means  of  ignition,  temperature,  pressure,  and  so  on.  In 
general,  the  mixture  that  has  just  enough  oxygen  for  com- 
plete combustion  of  the  fuel  gives  the  highest  pressures  and 
temperatures,  and  very  nearly  the  highest  speed  of  ignition. 
If  the  proportion  of  oxygen  (air)  is  increased  beyond,  or 
decreased  from,  the  theoretical  proportion,  the  maximum 
pressures  and  temperatures  are  lowered  and  the  speed  of 
ignition  decreases  until  at  certain  upper  and  lower  limits  the 
mixture  ceases  to  be  explosive,  and  only  slow  combustion  can 
occur. 

The  figures  here  given  are  believed  to  be  a  fair  average  of 
those  given  by  the  various  authorities.  The  explosion  is  sup- 
posed to  be  caused  by  an  electric  spark,  at  atmospheric  pressure 
and  a  temperature  of  about  65  deg.  F. 

Acetylene — 3  per  cent  gas  plus  97  per  cent  air  to  55  per  cent  gas 
plus  45  per  cent  air,  or  a  range  of  52  per  cent  (one  writer  says  73 
per  cent  gas  plus  27  per  cent  air). 

Blauyas — 4  per  cent  gas  plus  96  per  cent  air  to  8  per  cent  gas 
plus  92  per  cent  air,  or  a  range  of  4  per  cent. 

Coal  Gas — 6.5  per  cent  gas  plus  93.5  per  cent  air  to  19.5  per  cent  gas 
plus  80.5  per  cent  air,  or  a  range  of  13  per  cent. 

Drigas — 4  per  cent  gas  plus  96  per  cent  air  to  8  per  cent  gas  plus 
92  per  cent  air,  or  a  range  of  4  per  cent. 

Hydrogen — 10  per  cent  gas  plus  90  per  cent  air  to  66  per  cent  gas 
plus  34  per  cent  air,  or  a  range  of  56  per  cent  (one  writer  says  6 
per  cent  plus  94  per  cent  to  72  per  cent  plus  28  per  cent). 

.   Thermalene — 12  per  cent  gas  plus^  88  per  cent  air  to  30  per  cent 
gas  plus  70  per  cent  air,  or  a  range  of  18  per  cent. 

The  ignition  temperatures  of  some  of  the  gases,  at  at- 
mospheric pressure  are :  Acetylene,  760  to  820  deg.  F. ;  city 
gas,  1100  deg.  F. ;  hydrogen,  1075  to  1100  deg.  F. 

According  to  McCormack,  the  cu.ft.  per  pound  of  gases 
was  calculated  for  the  specific  gravity  and  found  to  be :  Acety- 
lene, 14.8  cu.ft.;  coal  gas,  24.3  cu.ft.;  hydrogen,  192.4  cu.ft.; 
thermalene,  13.97  cu.  ft. 


HISTORY  AND  USES  OF  THE  GAS  TORCH  7 

The  Field  of  Gas  Torch  Welding  and  Cutting. — In  a  general 
way,  the  field  of  the  gas  torch  welding  and  cutting  may  be 
outlined  as  follows,  though  some  of  the  applications  enume- 
rated are  more  advantageously  done  by  other  methods.  This 
is  especially  true  with  reference  to  the  welding  of  heavy  sec- 
tions which  should,  as  a  rule,  be  done  with  thermit. 

Airplane  Construction. — Welding  water  jackets  to  cylinder,  valve 
cages  to  cylinder,  of  manifolds  (intake,  exhaust,  and  cooling),  flanges 
to  the  manifold  connections,  spark  plug  thimbles,  tubular  sections  for 
frame,  splice  plates,  sockets  to  frames,  aluminum  crank  cases,  water 
tank. 

Automobile  Industry. — Welding  rear  axle  housings,  defective  gears 
and  pinions,  manifolds,  shafts,  steering  posts,  automobile  bodies 
(aluminum  and  steel),  tubing  used  in  wind  shields,  etc.,  crank  cases, 
transmission  cases,  wheels  which  are  made  of  stamped-out  parts, 
mufflers,  valve  stems  to  valves,  rims,  repairing  crank  shafts,  frames, 
extending  frame  to  make  a  truck  out  of  a  car. 

Copper  Plate. — Welding  manifolds,  flats,  kettles,  vats,  tanks,  copper, 
stills  and  chemical  ware. 

Electric  Railway. — Welding  of  bonds,  worn  boxes,  motor  housings, 
building  in  teeth  of  defective  pinions  and  gears,  reclaiming  of  broken 
trucks,  welding  air  receivers  on  air-brake  system,  steel  trolley  wires, 
side  frames. 

Forge  Shop. — Welding  ornamental  iron,   complicated  parts. 

Foundries. — Steel  foundry :  Welding  up  of  blowholes,  porous  spots, 
blocks,  cutting  of  risers,  gates  and  heads;  welding  moldings  which 
are  cast  in  parts.  Cast  iron  foundry :  Reclaiming  castings. 

Lead  Burning. — Burning  of  connectors  on  storage  batteries,  bat- 
tery repairs,  lead  linings  in  vats,  tanks,  etc.,  lead-pipe  joints. 

Piping  and  Gas  Main  Work. — Welding  of  steam,  air,  gas,  oil,  and 
water  lines,  welding  for  high  pressure  gas  distribution,  ammonia 
systems.  Fittings,  such  as  T's,  Y's,  S's,  crosses,  which  are  cut  and 
welded  on  the  job,  meter  connections  for  houses,  traps,  drip  pots. 

Plate  Welding. — Ammonia  receivers,  generators,  air  receivers,  tanks 
for  oil,  vacuum  driers,  digesters,  vats,  steam  driers,  tanks  of  all  kinds 
which  are  to  be  subjected  to  heat  and  pressure,  plate  assembly  work 
for  gas  manufacture  by-products,  recovery  work,  stills. 

Power  Plant  Maintenance. — Building  up  worn  or  broken  parts,  weld- 
ing of  cylinders,  pistons,  valve  chests,  etc.  Welding  of  steam  lines, 
of  pump  castings  broken  in  service.  Repairing  of  flywheels. 

Railroad  Repair. — Firebox  repairs  (including  patches),  replacing 
side  sheets,  welding  in  flues,  cutting  off  rails,  mud  rings,  welding 
cracked  steam  chest,  valves,  cross-heads,  cylinders,  building  up  worn 
pins,  cutting  out  links,  irregular  shapes  of  steel,  filling  worn  spots  on 
wheels,  welding  spokes,  cutting  and  welding  up  locomotive  frames. 
Welding  together  parts  of  car  seats,  chair  and  window  frames.  Re- 


8         GAS  TORCH  AND  THERMIT  WELDING 

claiming  bolsters,  couplings,  slotting  forged  engine  rods ;  building  up 
frogs  and  diamond  crossings,  scrappings,  building  steel  cars. 

Rolling  Mill. — General  repair  of  engines,  rolls,  hot  beds,  plates, 
furnace  equipment,  fabricating  open-hearth  water  jacket  doors,  re- 
claiming copper  tuyeres,  cutting  up  lost  heats,  cutting  up  "kindling" 
or  scrap,  bar  stock,  billets,  plates. 

Sheet  Metal. — Manufacture  of  metallic  furniture,  steel  barrels,  trans- 
former cases,  range  boilers,  kitchen  utensils,  light  air  tanks,  tubing, 
oil  storage  tanks. 

Shipyards. — Cutting  of  plates,  channels,  special  sections,  welding 
and  reclaiming  of  broken  parts  of  machinery  and  propellers,  patching 
of  hulls,  stringers,  building  up  of  worn  chocks. 

Small  Arms  Manufacture. — Reclaiming  component  parts,  spot  hard- 
ening of  different  parts,  spot  annealing. 

Structural  Steel. — Cutting  as  applied  to  coping,  splicing  and  fitting 
rails,  channels,  I  beams  and  other  shapes.  Cutting  holes  for  rivets, 
welding  up  misdrilled  holes,  cutting  of  all  kinds  of  gusset  splice  plates, 
cutting  wrecking,  welding  structural  parts  where  riveting  is  not 
possible. 


CHAPTER  II 

THE  PRODUCTION  OF  WELDING  GASES— OXYGEN 
AND  HYDROGEN 

Oxygen  is  a  gas  which  constitutes  about  23  per  cent  by 
weight  and  21  per  cent  by  volume  of  the  air  we  breathe,  most 
of  the  other  percentage  being  nitrogen,  a  gas  which  does  not 
support  combustion.  Oxygen  itself  will  not  burn,  but  it  is 
the  greatest  supporter  of  combustion  known.  It  was  probably 
discovered  by  Stephen  Hales  in  1727,  though  Priestly  was  the 
first  to  publish  a  description  of  it  in  1774.  The  name  ''oxygen" 
was  later  applied  to  the  gas  by  Lavoisier.  Pure  oxygen  is 
colorless,  odorless  and  tasteless.  For  welding  work  it  is  im- 
portant that 'the  oxygen  used  be  as  pure  as  it  is  commercially 
possible  to  obtain  it.  The  impurities  which  decrease  its  effi- 
ciency are  usually  hydrogen  and  nitrogen. 

There  are  three  ways  to  produce  oxygen  commercially;  by 
means  of  liquid  air,  by  chemicals  and  by  the  electrolytic 
process.  When  oxygen  is  made  by  the  liquid  air  process, 
there  is  a  certain  amount  of  nitrogen  present.  In  the  chemical 
methods,  a  number  of  impurities  may  cause  trouble.  By  the 
electrolytic  process,  the  impurity  is  hydrogen. 

Oxygen  by  the  Liquid  Air  Process. — As  a  general  rule, 
taking  everything  into  consideration,  it  is  far  better  for  the 
average  or  small  user  to  buy  his  oxygen  from  a  reliable  con- 
cern and  not  try  to  manufacture  it  himself.  The  oldest  concern 
in  this  country  making  oxygen  by  the  liquid  air  process  is  the 
Linde  Air  Products  Co.,  with  offices  in  New  York  City.  Their 
cylinders  are  regularly  furnished  in  two  sizes  of  100  and  200 
cu.ft.  capacity  respectively.  They  are  charged  to  a  pressure 
of  1800  jib.  at  a  temperature  of  70  deg.  F.  Customers  are 
furnished  cylinders  free  and  pay  only  for  the  oxygen.  Empty 
loaned  cylinders  are  exchangeable  for  filled  ones  at  stations  in 
practically  every  city  of  fair  size  in  the  country.  A  50  ft. 

9 


10  GAS  TORCH  AND  THERMIT  WELDING 

size  of  cylinder  is  obtainable  for  those  whose  requirements 
are  very  limited.  A  number  of  other  concerns  supply  elec- 
trolytic oxygen  for  the  market,  the  100  cu.ft.  cylinders  being 
about  8J  in.  in  diameter  and  48  in.  high,  weighing  approxi- 
mately 122  Ib.  when  filled.  The  average  purity  of  oxygen  in 
cylinders  is  about  99  per  cent. 

Since  the  production  of  oxygen  by  the  liquid  air  process 
is  only  applicable  to  large  installations  any  detailed  descrip- 
tion of  the  method  would  be  out  of  place  here.  It  is  sufficient 
to  say  that  in  general,  the  process  consists  of  first  reducing 
the  air  to  liquid  form  by  means  of  the  combined  action  of 
high  compression  and  low  temperature,  and  then  separating 
the  oxygen  and  nitrogen  of  which  it  is  composed,  by  taking 
advantage  of  the  different  boiling  points  of  the  two.  Under 
atmospheric  pressure  the  boiling  point  of  very  pure  liquid 
oxygen  is  — 182.7  deg.  C.  ( — 296.9  deg.  F.)  and  of  very  pure 
nitrogen  —195.5  deg.  C.  (—319.9  deg.  F.).  This  means  a  dif- 
ference in  the  boiling  points  of  12.8  deg.  C.,  or  23  deg.  F. 
These  respective  boiling  points  will,  of  course,  vary  under 
different  pressures,  and  various  degrees  of  purity,  but  the 
difference  between  the  two  is  sufficient  to  allow  of  the  nitrogen 
being  vaporized  in  suitable  apparatus  and  carried  away  before 
the  oxygen  vaporizes. 

The  Chlorate  of  Potash  Process. — Where  circumstances 
make  the  chemical  production  of  oxygen  advisable,  the 
chlorate  of  potash  method  is  probably  the  most  satisfactory 
at  the  present  time.  In  this  process  chlorate  of  potash 
(KC103)  and  manganese  dioxide  (Mn02)  are  mixed  together 
in  the  proportion  of  100  to  13  parts  (about  8  to  1).  This 
mixture  is  placed  in  a  retort  filled  as  full  as  possible  to  exclude 
air.  The  retort  is  then  heated  and  the  oxygen  is  driven  off.  As 
the  oxygen  gas  passes  off  from  the  retort  it  is  conveyed  through 
a  cylinder  or  vessel  containing  sodium  hydroxide  (NaOH) 
which  removes  most  of  the  impurities.  The  oxygen  is  then 
piped  to  a  gasometer  from  which  it  may  be  used  direct  or 
pumped  into  cylinders.  A  pound  of  the  mixture  is  said  to 
produce  about  4  or  4J  cu.ft.  of  oxygen.  The  manganese  diox- 
ide is  unchanged  during  the  process.  It  is  used  because  it 
enables  the  chlorate  of  potash  to  more  readily  give  up  its 
oxygen  and  at  a  lower  temperature  than  without  it. 


THE  PRODUCTION   OF  WELDING   GASES 


11 


An  oxygen  generator  working  on  the  general  principles 
just  outlined  is  made  by  the  Macleod  Co.,  Cincinnati,  Ohio. 
This  firm  makes  both  a  stationary  and  a  portable  type.  A 
stationary  type  is  shown  in  Fig.  1  and  a  portable  one  in 
Fig.  2.  The  generator,  which  consists  of  a  furnace  with  retort, 
a  scrubber  for  holding  the  purifying  solution,  and  a  receiver 


FIG.  1. — The  Buckeye  Chemical  Oxygen  Generating  Set. 

for  the  gas,  is  quite  convenient  for  small  shops  or  garages 
where  a  limited  amount  of  oxygen  is  used.  It  is  quite  possible, 
however,  to  fill  tanks  from  these  generators  for  storage  pur- 
poses and  immediate  use  if  needed.  An  oxygen  generator 
may  be  used  in  conjunction  with  a  cylinder  of  dissolved  acety- 
lene, or  with  a  separate  acetylene  generator.  Where  portable 


12 


GAS  TORCH   AND  THERMIT  WELDING 


generators  are  used  for  both  oxygen  and  acetylene,  it  is  ad- 
visable to  have  the  outfits  on  separate  trucks  so  as  to  decrease 
danger  should  any  leaks  develop. 

The  Buckeye  generator  is  so  made  that  it  is  adaptable  to 
the  use  of  wood,  coal,  coke  or  charcoal  for  fuel,  or  can  be  fitted 
with  gas,  gasoline,  alcohol  or  oil  burners.  The  portable  type 
is  shown  fitted  with  a  gasoline  burner.  The  generators  are 


FIG.  2. — Buckeye  Oxygen  Generator  Mounted  on  a  Truck. 

tested  to  2£  times  the  maximum  working  pressure  of  300  Ib. 
Safety  devices  are  provided  so  that  it  is  safe  for  practically 
unskilled  tenders.  These  generators  are  made  in  three  sizes, 
with  a  capacity  of  40,  60  and  100  cu.ft.  of  oxygen  per  hour. 
The  weight  of  the  portable  type  will  range  around  650  Ib. 
and  of  the  larger  stationary  type  about  1600  Ib. 


THE   PRODUCTION   OF  WELDING  GASES  13 

OXYGEN  AND   HYDROGEN   BY   THE   ELECTROLYTIC 

METHOD 

The  electrolytic  process  for  the  production  of  oxygen  is 
more  adapted  to  private  installations  than  the  liquid-air 
process.  An  electrolytic  installation  is  flexible,  and  may  be 
expanded  so  as  to  produce  any  commercial  quantity  of  gas 
desired  with  very  little  attention.  One  big  advantage  of 
this  process  is  that  hydrogen  is  produced  at  the  same  time 
as  the  oxygen,  and  in  many  cases  this  hydrogen  can  be  used 
to  advantage  for  welding,  cutting,  or  other  purposes. 

As  a  rule,  oxy-hydrogen  for  welding  is  less  desirable  than 
oxy-acetylene,.  but  for  some  purposes,  especially  when  there 
is  an  abundance  of  hydrogen  available,  it  is  very  satisfactory. 
The  heat  produced  by  the  oxy-hydrogen  flame  (about  2632 
deg.  F.)  is  considerably  less  than  that  of  the  oxy-acetylene 
flame  (about  6300  deg.  F.),  consequently  it  is  commonly  em- 
ployed for  welding  thin  metals,  lead  burning  or  other  work 
within  its  heat  range.  As  a  general  rule,  oxy-hydrogen  is  good 
for  welding  16-gage  steel,  or  thinner,  but  should  not  be  used 
on  steel  over  £  in.  thick.  As  hydrogen  contains  no  carbon, 
the  weld  is  softer  than  with  acetylene.  Cast  iron  up  to  }  in. 
in  thickness  may  be  successfully  welded,  as  may  also  aluminum 
crankcases  or  alloyed  metals.  For  cutting,  however,  oxy- 
hydrogen  has  a  wide  field,  especially  for  heavy  work. 

General  Principles  of  the  Electrolytic  Method. — In  an  ele- 
mentary form,  decomposition  of  water  may  be  effected  by 
passing  an  electrical  current  between  two  metallic  poles,  or 
electrodes,  immersed  in  water.  By  the  admixture  of  acid  or 
alkali,  forming  an  electrolyte,  the  resistance  of  the  water  is 
lowered  to  allow  a  large  current  of  electricity  to  pass,  pro- 
portionately raising  gas  production.  Simultaneously  with  the 
passage  of  current,  decomposition  of  water  into  its  components, 
oxygen  and  hydrogen,  begins.  Oxygen,  exhibiting  positive 
electrical  properties,  is  formed  on  the  positive  pole  or  "  anode  " ; 
double  quantity  of  hydrogen  is  formed  at  the  same  time  on 
the  negative  pole  or  "cathode."  The  gases  are  immediately 
available,  and  by  interposition  of  a  suitable  diaphragm  be- 
tween the  poles,  are  kept  separate  and  led  to  their  proper 
receivers. 


14  GAS   TORCH  AND  THERMIT  WELDING 

The  rapidity  of  decomposition,  and  consequently  the  amount 
of  gases  evolved  being1  in  direct  measure  of  the  electrical 
current  passing,  there  is  afforded  convenient  and  economical 
means  of  producing  commercial  oxygen  and  hydrogen.  The 
electrolytic  solution  increases  in  density  as  the  action  con- 
tinues. The  volume  of  water  dissociated  is  therefore  replaced 
at  regular  intervals. 

Complete  separation  of  the  gases  is  desirable  in  order  to 
insure  their  availability  at  high  purity.  This  involves  the 
use  of  a  diaphragm,  which,  immersed  in  the  solution,  will 
allow  passage  of  current  between  the  poles  and  at  the  same 
time  prevent  mixing  of  gases. 

The  production  of  oxygen  and  hydrogen  being  in  respect 
to  the  amount  of  current  passing,  it  is  apparent  that  the  voltage 
required  to  send  the  specified  amount  of  electricity  through 
the  electrolyzer  is  a  measure  of  the  efficiency  of  the  apparatus, 
since,  if  the  kilowatt-hour  consumption  is  known,  the  gas  pro- 
duction may  be  compared  with  it.  Thus,  there  has  been 
evolved  the  commonly  accepted  performance  rating  of  any 
electrolyzer  given  in  terms  of  cubic  feet  of  gas  produced  per 
kilowatt-hour  operation. 

The  production  of  pure  gases  is  very  important.  In  the 
earlier  types  of  water  electrolyzers  the  requirements  for  pro- 
ducing gases  of  high  purity  were  not  understood,  with  the 
result  that  means  of  purification  of  the  gases  after  generation 
were  necessary.  Devices  of  this  character  have  been  found 
expensive  to  maintain  and  inefficient  in  action.  Modern  de- 
signs of  electrolyzers  are  capable  of  delivering  oxygen  of  about 
99  per  cent,  and  hydrogen  of  equal  or  greater  purity,  so  that 
the  need  for  external  purifying  means  no  longer  exists. 

On  delivery  from  the  electrolyzers  the  gases  are  conducted 
separately  to  a  pressure  regulating  device  which  imposes  equal 
pressures  on  both  oxygen  and  hydrogen,  thus  equalizing  the 
pressures  on  each  side  of  the  separating  diaphragm.  The 
gases  are  then  passed  to  their  respective  gas  holders,  in  which 
they  are  collected  and  stored  at  a  few  ounces  pressure.  Upon 
the  nature  of  service  of  the  gases  will  depend  the  size  of  the 
gas  holders,  and  the  method  of  compressor  control. 

If  it  is  desired  to  compress  the  'gases  into  cylinders  for 
shipment,  as  in  the  case  of  a  commercial  plant,  large  gas 


THE   PRODUCTION  OF  WELDING   GASES  15 

holders  are  employed  having  capacity  for,  at  least,  a  con- 
tinuous day's  run  of  the  electrolyzers.  High-pressure  com- 
pressors draw  from  these  holders  and  discharge  to  a  manifold 
to  which  the  portable  cylinders  are  connected.  The  pressure 
carried  in  the  cylinders  is  usually  1600  to  1800  Ib.  per  sq.in. 
Cylinders  of  100  and  200  cu.ft.  capacity  will  weigh  about  85 
and  150  Ib.  respectively. 

There  are  many  oxy-hydrogen  producing  equipments  in- 
stalled in  industrial  establishments,  the  gases  being  utilized 
in  various  portions  of  the  works.  In  the  Davis-Bournonville 
installations,  gas  holders  of  moderate  size  are  employed,  their 
rise  and  fall  starting  and  stopping  the  compressor  motors 
through  automatic  electrical  control  devices. 

The  gases  may  be  stored  in  stationary  pressure  tanks  to 
a  moderate  amount,  these  being  fitted  with  automatic  regu- 
lators, so  that  when  they  are  filled  to  capacity,  the  entire 
plant  will  be  shut  down.  The  gases  are  piped,  where  desired, 
through  pressure  lines,  thus  avoiding  the  replacement  of  empty 
cylinders.  This  method  of  installation  is  particularly  desir- 
able for  continuous  welding  and  cutting  operations,  either  by 
hand  or  mechanical  means.  Provision  may  also  be  made  for 
charging  portable  cylinders  for  use  in  operations  carried  on 
at  isolated  points. 

Through  the  automatic  control  mentioned,  the  flexibility 
of  an  oxy-hydrogen  generating  and  compressing  equipment 
may  be  appreciated.  The  required  amount  of  attendance  being 
small,  and  needed  only  at  regular  intervals,  continuous  24- 
hour  operation  of  the  equipment  or  intermittent  service,  if 
desired,  is  quite  feasible  and  practicable.  If  maximum  pro- 
duction is  not  desired,  reducing  the  current  passing  thr.ough 
the  electrolyzers  will  proportionately  lower  the  volume  of  gas 
that  is  being  generated. 

Details  of  the  Davis  Electrolyzer  Cell. — For  various  reasons, 
electrolytic  installations  are  made  up  of  small  units  or  cells, 
which  may  be  combined  in  such  a  way  as  to  produce  any 
required  amount  of  gas.  Details  of  an  electrolyzer  cell  are 
shown  in  Fig.  3.  This  type  of  cell  is  made  by  the  Davis- 
Bournonville  Co.,  Jersey  City,  N.  J.  The  type  illustrated 
provides  current  conducting  areas  and  gas  generating  sur- 
faces amply  proportioned  to  their  requirements.  There  is  suffi- 


16  GAS  TORCH  AND  THERMIT  WELDING 

cient  over-capacity  to  minimize  electrical  resistance  and  afford 
high  working  efficiency.  Long  life  of  the  vital  parts  is  also 
insured.  Research  has  shown  that  a  nickel-iron-alkali  com- 
bination of  elements  employed  for  electrolytic  dissociation  of 
water  is  a  very  efficient  selection  from  an  electrical  input  and 
gas  producing  standpoint.  Parts  subject  to  deteriorating  action 
of  any  character  are  constructed  of  special  material  and  pro- 
tected by  processes  especially  adapted  to  service  requirements. 
Care  has  been  exercised  in  the  design  so  as  to  avoid  com- 
plication of  electrical  and  mechanical  connections  of  small 
cross-section.  Thus  studs,  bolts,  busbars  and  their  contacts 
are  amply  large  for  all  purposes. 

These  electrolyzers  are  manufactured  in  two  sizes,  operating 
on  specified  currents  of  500  and  1000  amp.  respectively.  The 
dimensions  of  the  respective  cells  are  54  and  61^  in.  high, 
13J  and  15J  in.  thick  and  24J  and  36  in.  wide.  The  height 
given  is  from  the  bottom  of  the  cell  to  the  center  of  the  highest 
horizontal  tube,  through  which  the  hydrogen  passes  into  the 
service  pipe. 

In  stating  the  production  of  gases  evolved  by  dissociation 
of  water  the  commonly  accepted  formula  employed  specifies 
production  of  7.93  cu.ft.  of  Oxygen  with  double  quantity  of 
hydrogen  per  kilo-ampere-hours  at  normal  temperature  and 
pressure.  The  normal  production  of  Davis-Bournonville  elec- 
trolyzers may  therefore,  according  to  their  booklet,  be  stated  as 
follows : 

Normal  Hourly  Gas  Production 

Type  Amperage  Oxygen  Hydrogen 

5  500  3.96  cu.ft.  7.92  cu.ft. 

6  1000  7.92      "  15.84      " 

at  20  deg.  C.  and  760  nun.  barometer. 

The  closed-cell  type  of  construction  adopted  eliminates  the 
absorption  of  carbon  dioxide  (C02)  by  the  solution  exposed 
to  the  atmosphere  in  the  open  type  of  electrolyzer,  and  its 
consequent  deteriorating  effect  upon  the  electrolyte  and  purity 
of  gases.  Electrical  current  passing  through  the  electrolyzer 
is  converted  almost  entirely  into  chemical  energy  for  producing 
oxygen  and  hydrogen.  There  being  practically  no  action  on 
the  electrolyte  employed  as  a  conducting  medium  between 
the  poles  other  than  the  dissociation  of  water,  it  is  evident 


THE  PRODUCTION  OF  WELDING   GASES 


17 


that  the  electrical  pressure  or  voltage  required  to  send  the 
specified  amount  of  electrical  energy  through  the  apparatus 
is  a  measure  of  its  efficiency. 

Referring  now  to   the   illustration,   it  should  be   kept  in 


FIG.  3. — Details  of  the  Davis  Electrolyzer  Cell. 

mind  that  the  solution  used  is  water  with  certain  chemicals, 
such  as  sodium  hydroxide  (caustic  soda)  or  potassium 
hydroxide  (caustic  potash),  added  to  increase  the  conductivity. 
The  reservoir  in  which  the  solution  is  placed,  is  divided  by 


18  GAS  TORCH  AND  THERMIT  WELDING 

a  metal  plate  A.  Anodes  B  are  suspended  on  each  side  of  this 
plate,  and  on  these  the  oxygen  forms.  The  cell  itself  is  made 
of  metal,  and  the  walls  of  this,  as  well  as  the  sides  of  the 
metal  plate  A,  form  the  cathode  or  negative  pole  from  which 
the  hydrogen  gas  rises.  To  keep  the  oxygen  and  hydrogen 
separated,  asbestos  sacks  C  are  so  placed  as  to  surround  each  of 
the  two  anodes.  The  oxygen  generated  passes  up  through  the 
hard  rubber  tubes  D  connected  to  the  pipe  E.  The  hydrogen 
passes  up  tube  F  into  pipe  G.  The  current  to  the  anodes  is 
conducted  through  the  positive  busbar  assembly  H.  The  nega- 
tive busbar  assembly,  shown  at  /,  is  attached  to  and  forms 
part  of  the  cast-iron  cover  of  the  cell  and  connects  with  the 
center  plate  and  the  tank  walls.  Valves  for  the  three  gas  tubes 
are  indicated  by  J.  As  the  current  passes  through  the  cell 
the  entire  solution  is  charged  and  this  results  in  the  freeing  of 
oxygen  at  the  anodes  and  hydrogen  at  the  cathodes.  Since 
these  gases  have  no  tendency  to  pass  off  anywhere  except  at  the 
respective  terminals  in  the  cell,  the  asbestos  curtain  effectively 
keeps  them  separated.  The  pressure  of  the  two  gases,  how- 
ever, must  be  kept  the  same  or  the  one  having  the  higher 
pressure  will  be  forced  through  the  fabric  of  the  asbestos  sacks 
and  mix  with  the  other  gas.  This  is  taken  care  of  by  having 
the  gases  from  the  pipes  E  and  G  pass  through  a  combined 
flash-back  and  pressure  regulator.  The  function  of  this  device 
is  to  receive  the  gases ;  regulate  their  pressure  through  a  simple 
water  seal  which  equalizes  the  gas  pressures  inside  the  elec- 
trolyzer ;  separate  and  return  to  the  cell  any  alkali  carried 
over ;  provide  means  of  replacement  of  water  to  the  cell ;  bypass 
gases  to  the  air  if  the  delivery  lines  become  obstructed,  and  to 
prevent  admission  of  any  flame  to  the  electrolyzer. 

The  replacement  of  distilled  water,  as  needed,  is  made 
through  the  reservoir  K,  which  combines  the  replacement  func- 
tion with  that  of  a  hydraulic  governor  automatically  adjusting 
the  inner  level  of  the  solution.  Under  operating  conditions, 
the  usual  replacement  of  distilled  water  amounts  to  approxi- 
mately one  gallon  per  100  cu.ft.  of  oxygen  and  200  cu.ft.  of 
hydrogen.  This  replacement  and  the  ordinary  inspection  usually 
given  to  the  electrical  apparatus  is  practically  all  the  atten- 
tion required  for  a  battery  of  cells. 

The    International    Oxy-Hydrogen    Generator.— The    elec- 


THE  PRODUCTION   OF  WELDiNG  GASES 


19 


trolytic  cell  shown  in  Fig.  4  and  in  further  detail  in  Fig.  5, 
is  made  by  the  International  Oxygen  Co.,  New  York.  Each 
cell  unit  requires  a  floor  space  4  X  40  in.,  and  with  the  neces- 


Fio.  1.  —Cell  Made  by  the  International  Oxygen  Co. 

sary  pipe  connections,  a  head  room  of  about  6  ft.  These  cells 
are  intended  to  be  run  on  a  normal  amperage  of  600  and 
a  voltage  of  2.2  each,  using  a  caustic  soda  solution.  The 


20 


GAS  TORCH  AND   THERMIT  WELDING 


possible  range  above  and  below  the  normal  amperage  is  con- 
siderablej  without  injury  to  the  cells.  An  equipment  of  their 
type  4-1000  cells  can  be  operated  with  good  economy  over  a 
current  range  of  less  than  200  up  to  1000  amp.,  representing 
a  production  range  of  more  than  one  to  five.  In  actual  figures 
this  means  that  an  installation  giving  600  cu.ft.  of  oxygen 


WATER    FEED 


ESERVOIR 
FOR 
ELECTROLYTE 


ELECTRICAL 

CONNECTIONS 


PETTICOAT 
INSULATOR 


FIG.  5. — Some  Details  of  the  Cell  Construction. 

and  1200  cu.ft.  of  hydrogen  per  24  hours,  at  600  amp.,  can 
by  varying  the  current  and  without  any  alteration  in  the 
plant,  be  made  to  deliver  from  less  than  200  cu.ft.  of  oxygen 
and  400  cu.ft.  of  hydrogen,  to  more  than  1000  cu.ft.  of  oxygen 
and  2000  cu.ft.  of  hydrogen  per  24  hours.  Operating  at  200 
amp.,  the  power  consumption  per  unit  of  gas  generated  is  16 
per  cent  less  than  the  normal  600-amp.  operation.  When 


THE   PRODUCTION   OF   WELDING   GASES 


21 


operating  at  1000  amp.,  the  power  consumption  per  unit  of 
gas  is  15  per  cent  more  than  at  600  amp. 

Local  rates  will  largely  govern  the  number  of  cells  required 
for  a  given  output  of  the  gases.     Where  the  cost  of  current 


FIG.  6.— A  Group  of  I.  O.  C.  Cells. 

is  low,  the  plant  can  be  economically  run  on  current  above 
600  amp.,  the  increased  production  per  hour  giving  the  re- 
quired amount  with  fewer  cells,  since  the  lower  current  cost 
justifies  the  slightly  lower  electrical  efficiency.  Where  the 


22 


GAS  TORCH  AND   THERMIT  WELDING 


price  of  current  is  high,  it  will  be  advantageous  to  use  current 
less  than  600  amp.,  thus  taking  advantage  of  the  higher  elec- 
trical efficiency,  but  more  cells  will  be  needed. 

In  general  principles,  this  make  of  cell  resembles  the  one 


wttcnboanl  con-} 

necfed  fo  source 

of  current 


FIG.  7. — Suggested  Layout  of  a  50-Cell  Plant. 

previously  described,  though  different  in  form.  By  referring 
to  the  illustration,  it  will  be  seen  that  a  cell  is  made  up  of  a 
thin  rectangular-shaped  box  frame  to  the  sides  of  which  are 
bolted  two  cast-iron  plates  or  electrodes.  The  cavities  formed 
between  the  center  and  side  plates  are  divided  by  asbestos 


THE  PRODUCTION  OF  WELDING  GASES 


23 


fabric  diaphragms,  forming  two  chambers.  The  asbestos  dia- 
phragms are  clamped  directly  by  metal  and  are  not  held  in 
place  by  either  rubber  or  cement.  In  the  upper  part  of  the 


CYLINDER'    STORAGE 
AND     CHARGING     ROOM 


FIG.  8.— Suggested  Layout  of  a  200-Cell  Plant. 

cast-iron  frame  are  reservoirs  for  the  electrolyte,  from  which 
it  is  fed  to  the  two  sides  of  the  diaphragms.  There  are  also 
two  gas  chambers  at  the  top  of  the  frame,  which  serve  as  gas 
traps  and  gas  take-offs,  as  well  as  an  automatic  pressure- 

1 


24  GAS  TORCH  AND   THERMIT  WELDING 

controlling  device.  At  the  bottom  of  the  frame  are  com- 
municating passages  which  permit  the  equalization  of  densities 
in  the  electrolyte.  The  cells  are  constructed  of  material  which 
make  them  practically  indestructible.  Each  cell  is  provided 
with  an  eye-bolt  to  facilitate  handling.  The  electrodes  are 
provided  with  a  large  number  of  pyramidal  projections  which 
greatly  increase  the  area  of  contact  with  the  electrolyte  and 
facilitate  the  release  of  the  gases  at  the  generating  surfaces. 
At  600  amp.  the  production  of  a  plant  per  24  hours  is  105 
cu.ft.  of  oxygen  and  210  cu.ft.  of  hydrogen  per  square  foot  of 
floor  space.  A  group  of  cells  is  shown  in  Fig.  6. 

Two  typical  plant  layouts  are  shown  in  Figs.  7  and  8. 
Fig.  7  is  a  layout  for  a  50-cell  plant,  with  a  normal  capacity 
of  5760  cu.ft.  of  oxygen  and  twice  as  much  hydrogen.  This 
plant  may  be  put  in  a  corner  of  an  existing  building,  and 
requires  a  space  22  X  24  ft.  It  is  complete  with  all  accessories 
except  gas  holders  and  storage  tanks.  Fig.  8  is  a  separate 
plant  of  200  cells,  with  all  necessary  accessories — such  a  plant 
as  might  be  installed  for  public  service  in  cylinders  for  gas 
users.  Its  main  dimensions  are  53  X  79  ft.  and  it  has  a  normal 
capacity  of  23,040  cu.ft.  of  oxygen  and  46,080  cu.ft.  of  hydrogen 
per  24  hours. 

The  Levin  Type  of  Generator. — The  generator  made  by  the 
Electrolytic  Oxy-Hydrogen  Laboratories,  Inc.,  Dayton,  Ohio, 
and  also  of  New  York,  is  the  design  of  I.  H.  Levin,  after  whom 
it  is  named.  It  is  of  the  unit  type,  and  is  made  up  of  a  few 
standardized  parts  which  can  be  easily  assembled.  Details 
of  one  of  the  cells  are  shown  in  Fig.  9.  From  this  it  will  be 
seen  that  in  the  main  the  general  construction  is  the  same 
as  others  on  the  market.  One  noticeable  difference  from  those 
described,  however,  is  that  the  electrodes  are  made  independent 
of  the  casing,  being  separated  from  and  securely  fixed  within 
the  casing  by  specially  designed  blocks  of  asbestos. 

Each  compartment  has  an  independent  water  feed  which 
also  serves  as  a  blow-off  device  to  vent  the  gases  under  ab- 
normal conditions.  The  surfaces  of  both  the  anode  and 
cathode  are  plated  with  cobalt,  which  is  said  to  lower  the 
over-voltage  in  excess  of  what  the  gas  electrodes  require. 
The  cells  are  sent  out  entirely  welded,  and  completely  and 
rigidly  assembled,  so  that  they  may  be  filled  with  electrolyte, 


THE   PRODUCTION   OF   WELDING   GASES 


25 


connected  up,  and  put  into  service  immediately.  Each  cell 
is  6J  in.  thick,  25  in.  wide  and  30  in.  high,  and  weighs  185  Ib. 
With  the  ground  supports,  porcelain  insulators  and  the  piping 
system  above,  the  total  height  is  4  ft.  8  in.,  which  brings  all 
the  parts  within  the  range  of  normal  reach  and  vision.  Even 


OXYGEN  OFFTAKE  PIPE 
'  TAPFOR\ 
J-4f  PS  .]\.,  HYDROGEN  OFFTAKE  PIPE 

Minimum  space  to  be  connected 
by  rub 


•OXYGEN  SIGHT  FEED  INDICATOR 
HYDROGEN  SIGHT  FEED  INDICATOR 

0 


OUTER  CASING 

INSULATOP.. 

FRAME  FOR  ASBESTOS      ---- 


ASBESTOS  DIAPHRAGM     - 

CATHODE 


ASBESTOS  INSULATORS 


PORCELAIN  INSULATORS 
Floor  Line 


FIG.  9. — Cross-Section  of  the  Levin  Generator  Cell. 

a  minimum  aisle  space  of  30  in.  will  leave  ample  room  for  the 
removal  or  replacement  of  any  cell.  Each  cell  is  intended 
to  operate  at  a  normal  amperage  of  250,  requiring  a  little 
over  4/io  kw.  per  hour.  A  battery  of  1000  cells  will  occupy 
a  space  4|  X  31  ft.  and  is  claimed  to  produce  200  cu.ft.  of 
oxygen  and  400  cu.ft.  of  hydrogen  per  hour. 


CHAPTER  III 

ACETYLENE  AND  MEDIUM,  OR  POSITIVE,  PRESSURE 
GENERATORS 

Ac';tyiene,  which  is  the  gas  most  commonly  used  with 
oxygen  for  gas-torch  welding,  is  produced  by  the  reaction 
between  calcium  carbide  and  water.  It  is  used  because  of  its 
large  carbon  content  and  also  because  of  its  endothermic 
properties,  which  means  that  it  is  heat  absorbing  and  energy 
stored  up  in  its  formation  is  given  off  again  upon  dissociation. 
Calcium  carbide  and  water  produce  acetylene  and  slacked  lime, 
the  formula  being:  CaC2  +  2H20  =  C2H2  +  CaO(H20).  The 
calcium  carbide  when  in  contact  with  water  is  divided  and 
the  carbon  of  the  carbide  joins  with  the  hydrogen  of  the  water 
to  form  acetylene  gas.  The  calcium  of  the  carbide  unites  with 
the  oxygen  of  the  water  and  forms  slaked  or  hydrate  of  lime, 
as  just  stated. 

Since  calcium  carbide  combines  with  water  in  all  of  its 
forms  it  must  be  protected  from  moisture  in  handling.  For 
this  reason  it  is  shipped  in  sealed  metal  drums  or  cans  com- 
monly holding  100  Ib.  From  these  drums  the  carbide  is  placed 
in  generators  for  the  purpose  of  liberating  the  gas. 

Like  other  gases  used  for  welding  or  cutting  purposes, 
acetylene  may  be  purchased  in  cylinders,  but  it  cannot  be 
compressed  directly  into  ordinary  steel  cylinders  with  safety. 
When  compressed  to  as  much  as  30  Ib.  per  sq.in.,  it  becomes 
very  unstable  and  liable  to  explode  unless  handled  with  ex- 
treme care.  The  heat  generated  by  compression  therefore 
makes  this  a  dangerous  process  unless  means  are  provided  for 
cooling.  The  method  used  in  order  to  compress  the  gas  and 
make  it  safe  to  handle  is  to  fill  the  cylinders  with  some  porous 
substance  and  then  fill  them  with  acetone.  Acetone  is  a  liquid 
that  has  the  property  of  absorbing  acetylene  about  the  way 
sugar  does  water,  and  acetylene  in  this  state  is  commonly  known 
as  dissolved  acetylene.  As  acetone  takes  up  acetylene  it  in- 

26 


ACETYLENE  AND   MEDIUM   PRESSURE   GENERATORS        27 

creases  in  bulk.  So  suppose  a  cylinder  to  be  filled  only  with 
acetone  and  dissolved  acetylene  under  considerable  pressure. 
If  the  cylinder  gas  valve  is  opened  and  some  of  the  acetylene 
drawn  off,  the  acetone  will  shrink  in  volume  and  leave  a  place 
in  the  cylinder  filled  with  undissolved  acetylene  gas  under 
pressure.  This  free  acetylene  under  pressure  is  very  explosive, 
and  easily  set  off  from  shock  or  heat.  However,  it  has  been 
found  that  the  gas  will  not  dissociate  when  finely  divided,  and 
advantage  is  taken  of  this,  and  the  cylinder  or  tank  is  filled 
with  porous  material.  For  this  purpose  a  mixture  of  asbestos, 
charcoal,  kieselguhr,  and  a  small  amount  of  cement  to  hold 
it  together,  is  packed  into  the  cylinder  or  tank,  providing  a 
finely  divided  porous  filling  that  prevents  dissociation  of  the 
gas.  After  a  cylinder  has  been  completely  filled  with  this 
mixture,  slightly  dampened,  it  is  baked  in  an  oven  until  the 
moisture  is  completely  driven  off.  It  is  then  exhausted  of  air 
and  acetone  is  introduced  into  the  cylinder.  Acetylene  is  then 
forced  into  this  prepared  cylinder,  by  means  of  a  specially 
cooled,  multiple-stage  pump,  great  care  being  exercised  during 
the  process.  Each  cubic  foot  of  acetone  will  absorb  24  cu.ft.  of 
acetylene  for  each  atmosphere  (15  Ib.)  of  pressure.  However, 
in  actual  practice,  the  quantity  of  acetone  in  a  cylinder  is 
usually  so  regulated  that  the  cylinder  will  contain  about  10 
times  its  own  volume  of  acetylene  for  each  atmosphere  of 
pressure  that  is  on  the  gas.  Cylinders  are,  as  a  rule,  charged 
to  15  atmospheres  pressure  at  60  deg.  F.,  so  they  contain  150 
times  their  own  volume  when  charged.  Thus  a  cylinder  that 
would  hold  2  cu.ft.  of  water  when  empty  will  hold  300  cu.ft. 
of  acetylene  at  225  Ib.  pressure,  60  deg.  F. 

The  filling  material  must  be  so  placed  in  the  cylinder  as 
not  to  settle  when  handled  or  shipped,  since  if  it  does,  a  danger- 
ous pocket  will  be  formed  filled  with  free  gas.  In  handling 
these  cylinders,  it  should  always  be  kept  in  mind  that  the 
pressure  increases  as  the  temperature  is  increased.  The  best 
results  are  obtained  by  keeping  the  cylinders  of  dissolved  acety- 
lene at  about  60  or  65  deg.  F.  An  average  cylinder  of  about 
100  cu.ft.  capacity  will  weigh  about  85  Ib.  and  one  of  300  cu.ft. 
capacity,  about  220  Ib.  A  Davis-Bournoiiville  cylinder,  12  X  36 
in.,  225  cu.ft.  capacity,  will  weigh,  fully  charged,  about  180 
pounds. 


28  GAS  TORCH  AND  THERMIT   \\ELDING 

Acetone  Injurious  to  a  Weld. — Acetone  is  very  injurious 
to  a  weld,  and  in  using  gas  from  a  cylinder  of  dissolved  acety- 
lene, care  must  be  exercised  not  to  use  the  gas  too  fast  or 
acetone  will  be  drawn  off  with  it.  The  allowable  rate  of  cylinder 
discharge  is  at  the  rate  of  one-seventh  of  the  capacity  per  hour. 
That  is,  a  225-cu.ft.  cylinder  will  supply  225  -^-  7  =  32  cu.ft. 
per  hour.  Under  emergency  conditions  this  rate  may  be  con- 
siderably exceeded,  but  the  practice  is  not  economical  and  is 
liable  to  injure  the  weld. 

The  amount  of  gas  in  any  cylinder  may  be  found  by  noting 
the  empty  or  tare  weight  stamped  on  the  cylinder,  then  weigh- 
ing the  cylinder  and  multiplying  the  difference  in  pounds  by 
14^.  In  some  cases  the  weight  marking  may  be  different,  but 
in  any  case,  each  pound  by  weight  of  dissolved  acetylene  is 
calculated  to  produce  14^  cu.ft.  of  gas.  To  calculate  the  amount 
of  acetylene  used  on  any  job,  weigh  the  cylinder  before  and 
after  and  multiply  the  difference  in  pounds  by  the  number 
just  given.  Knowing  the  cost  of  a  cylinder  of  gas,  the  cost  of 
the  amount  of  gas  used  on  any  job  may  be  easily  found. 

Weighing,  which  has  just  been  outlined,  is  the  only  ac- 
curate method  of  computing  the  amount  of  acetylene,  since 
gage-pressure  readings  are  affected  by  changes  of  temperature. 
However,  gage  pressures  are  a  ,great  convenience  in  estimating 
roughly  how  much  gas  remains  in  a  cylinder.  In  the  case  of 
a  100-cu.ft.  cylinder,  each  15  Ib.  of  pressure  represents,  ap- 
proximately, 6^  cu.ft.  of  gas,  and  in  a  300-cu.ft.  cylinder  each 
15  Ib.  of  pressure  represents,  approximately,  20  cu.ft.  of  gas. 

There  are  three  ty*pes  of  acetylene  generators,  the  essential 
differences  being  the  method  of  bringing  the  carbide  and  water 
into  contact.  These  three  methods  are:  dropping  the  carbide 
into  the  water;  allowing  the  water  to  rise  slowly  into  the 
carbide;  dropping  the  water  onto  the  carbide.  The  first  is  by 
far  the  most  satisfactory  method  and  the  one  generally  used 
in  the  United  States,  and  for  this  reason  will  be  the  only  method 
described. 

The  carbide-to- water  generators  are  of  two  types,  known 
as  positive-  or  medium-pressure,  generators  which  deliver  the 
acetylene  at  a  pressure  of  more  than  1  Ib.  and  not  to  exceed  15  Ib., 
and  low-pressure  generators  which  deliver  gas  at  a  pressure  of 
loss  than  1  Ib.  While  there  are  a  number  of  firms  making  the 


ACETYLENE  AND   MEDIUM   PRESSURE   GENERATORS       29 

different  types,  only  the  better  known  makes  will  be  described 
in  detail,  since  the  general  principles  are  the  same.  Modern 
generators  of  all  types  are  automatic  in  their  action,  the  feed 
being  regulated  by  the  flow  of  gas,  and  they  are  provided  with 
an  ample  number  of  fool-proof  devices  which  render  their  opera- 
tion and  handling  safe. 

The  Positive-Pressure  Generator. — The  first  positive-pres- 
sure generator  built  was  designed  by  Mr.  Bournonville  in  1906. 
The  present  type  of  pressure  generator  handled  by  the  Davis- 
Bournonville  Co.,  is  made  by  the  Davis  Acetylene  Co.,  Elkhart, 
Ind.  These  generators  are  made  in  several  sizes  to  meet  the 
demands  of  various  sized  shops,  and  they  may  be  had  in  25, 
50,  100,  200  and  300  Ib.  carbide  capacity.  These  numbers  in- 
dicate the  weight  of  the  charge  of  calcium  carbide  to  be  used, 
the  number  of  gallons  of  water  per  charge,  and  also  the  number 
of  allowable  cubic  feet  of  gas  generated  per  hour  in  accordance 
with  the  rules  of  the  National  Board  of  Fire  Underwriters. 

The  generators  of  50  Ib.  and  100  Ib.  capacity  are  standard 
for  repair  shops  and  light  manufacturing,  while  the  larger  sizes 
provide  for  more  extensive  and  continuous  use  in  large  repair 
shops  and  metal-working  industries.  They  are  of  heavy  con- 
struction with  powerful  feeding  mechanism.  They  are  fre- 
quently installed  as  units  to  build  up  plants  for  any  require- 
ments of  the  oxy-acetylene  process.  They  all  have  automatic 
feed  with  independent  power  and  the  quantity '  of  carbide  re- 
maining in  the  hopper  is  constantly  indicated.  The  acetylene 
gas  is  piped  directly  from  the  generator  under  the  required 
pressure  through  service  pipe  lines  to  the  welding  stations  and 
is  regulated  by  means  of  reducing  valves  fitted  with  pressure 
gages  to  govern  the  proper  working  pressure. 

The  size  of  carbide  used  in  the  Davis  stationary  generators,  is 
designated  as  1J  X  f  in->  and  it  is  estimated  to  produce  ap- 
proximately 4J  cu.ft.  of  acetylene  gas  to  a  pound  of  carbide. 
The  size  of  carbide  just  quoted  has  reference  to  the  size  of 
screen  mesh  it  will  go  through  or  not,  that  is :  1^  by  f  in,  means 
that  the  lumps  will  all  go  through  a  1-]-  in.  mesh  screen,  but 
none  through  a  §-in.  mesh;  carbide  quoted  as  J  by  TV  in.  size, 
will  go  through  a  -£-in.  mesh  screen,  but  not  through  a  i-in. 
mesh,  and  so  on.  This  smaller  size  is  estimated  to  yield  about 
4  cu.ft.  of  gas  per  pound  of  carbide. 


30 


GAS   TORCH   AND   THERMIT   WELDING 


The  carbide-to-water  generators  are  designed  to  hold  a  gallon 
of  water  for  each  pound  of  carbide  capacity.  In  practice  the 
carbide  is  fed  into  the  water  only  in  sufficient  quantity  to 
maintain  the  gas  supply  at  the  required  pressure.  The  extreme 
limit  of  safety  pressure  for  free  acetylene  is  30  Ib.  and  in  the 


FlG.  10. — Stationary  Type  of  Positive-Pressure  Acetylene  Generator. 

positive-pressure  types  of  generators  the  pressure  limit  is  placed 
at  15  Ib.  When  this  pressure  is  reached,  the  various  safety 
devices  begin  to  act  to  prevent  further  generation  and  conse- 
quent increase  in  pressure.  As  the  carbide  is  fed  from  the 
containing  hopper  it  drops  down  into  the  tank  of  water  beneath, 


ACETYLENE  AND   MEDIUM   PRESSURE   GENERATORS       31 


View  of  Motor  and  Filling! 
Plug  locking  Mechanism? 


Feeding 

Diaphragm  UDIOWOTT  ff^  Taf) 

FIG.  11.— Details  of  300  Lb.  Carbide  Capacity  Acetylene  Generator. 


32  GAS   TORCH   AND   THERMIT  WELDING     ; 

and  sinks  to  the  bottom.  In  this  way  most  of  the  gas  is  gen- 
erated close  to  the  bottom  of  the  water  tank,  and  has  to  rise 
through  a  considerable  body  of  water  to  reach  the  top.  This 
not  only  serves  to  cool  the  gas  but  also  washes  out  a  large  part 
of  the  impurities.  The  carbide  used  in  these  generators  may 
be  obtained  from  distributing  points  in  nearly  all  of  the  large 
cities  in  the  country,  in  sealed  drums  containing  100  pounds. 

The  acetylene  generator  shown  in  Fig.  10  is  the  Davis 
standard  stationary  300  Ib.  carbide  capacity  apparatus.  It  is 
115  in.  high,  42  in.  in  diameter,  and  weighs  about  1000  Ib. 
Details  of  this  apparatus  are  shown  in  Fig.  11.  In  this  cut, 
A  is  the  hopper  into  which  the  carbide  is  introduced  from  the 
top.  A  feeding  mechanism  at  the  bottom  of  this  hopper  is 
run  by  the  clock  motor  B,  which  is  operated  by  means  of  the 
weight  C.  The  feeding  device  consists  principally  of  a  rotating 
disk  with  inclined  vanes  which  sweep  the  lumps  of  carbide  off 
into  the  water  below.  There  are  two  safety-pressure  diaphragms 
for  stopping  the  motor  should  the  gas  pressure  become  too 
high.  The  first  diaphragm  acts  when  the  pressure  reaches  15 
Ib.  If  this  should  fail  to  act  properly,  the  second  diaphragm 
will  be  actuated  a  little  above  15  Ib.  pressure.  This  last  dia- 
phragm operates  a  positive  lock  which  effectually  stops  the 
motor  and  consequently  the  carbide  feed.  In  addition  to  this, 
there  is  a  safety  valve  at  E  which  is  connected  to  a  pipe  leading 
to  the  outside  of  the  building,  so  that  the  gas  can  escape  in 
safety.  At  Z>  is  a  funnel  by  which  water  is  run  into  the  tank. 
As  the  gas  is  generated  it  is  carried  through  the  pipe  F  to  the 
bottom  of  the  flash-back  chamber  G.  This  chamber  is  full  of 
water  and  serves  the  double  purpose  of  giving  the  gas  a  second 
washing,  and  acting  as  a  water  seal  between  the  service  pipe 
and  the  gas  in  the  generator.  From  this  chamber  the  gas  passes 
up  through  the  filter  chamber  H,  which  is  filled  with  asbestos 
that  removes  suspended  impurities.  From  this  filter  the  gas 
passes  out  through  valve  /  into  the  service  pipe  and  thence  to 
the  torches.  The  handle  J  operates  the  agitator  and  the  tank 
settlings  are  removed  through  the  gate  valve  K. 

In  addition  to  the  regular  stationary  type,  the  Davis-Bournon- 
ville  Co.  makes  what  is  called  a  "Navy  Type."  These  comprise 
a  complete  equipment  for  use  in  ship-building  yards,  railway 
systems,  and  large  industries.  The  installations  provide  acetylene 


ACETYLENE  AND   MEDIUM   PRESSURE  GENERATORS       33 


34 


GAS  TORCH   AND  THERMIT  WELDING 


ACETYLENE  AND  MEDIUM  PRESSURE  GENERATORS   35 

generation  with  two-pressure,  air-excluding  generators  of  large 
capacity,  supplying  acetylene  under  direct  pressure  to  welding 
and  cutting  stations  and  an  additional  low-pressure  supply  for 
compression  into  portable  safety  cylinders,  with  purification  sys- 


FIG.  14. — All-Steel  Hand  Truck  for  Holding  Gas  Cylinders  and 
Welding  Outfit. 

tern,  and  three-stage  specially  designed  acetylene  compressor. 
Three  sizes  of  the  navy  type,  two  pressure,  air-excluding  acety- 
lene generators  are  manufactured,  having  a  capacity  of  100  lb., 
200  lb.,  and  300  lb.  of  carbide  each,  and  with  normal  output  of 


36  GAS  TORCH  AND  THERMIT  WELDING 

100,  200  and  300  cu.ft.  of  acetylene  per  hour  respectively. 
When  greater  capacity  than  300  cu.ft.  of  acetylene  per  hour 
is  desired,  two  or  more  generators  may  be  connected  serially  with 
a  special  purifying  and  compressing  plant. 

A  navy  type  installation  is  shown  in  Fig.  12  and  a  suggested 
plant  layout  in  Fig.  13.  One  of  the  special  features  of  the 
navy  installation  is  the  low-pressure  supply  from  which  the 
gas  is  drawn  for  charging  portable  cylinders.  This  is  done 
because  in  many  places  around  a  shipyard  or  other  large  plants, 
it  would  be  practically  impossible  to  pipe  the  gas  or  to  use  a 
portable  generator.  The  cylinders  used  are,  of  course,  previously 
prepared  as  already  outlined.  After  charging  they  may  be 
transported  to  the  work  in  various  ways,  but  for  convenience 
they  may  be  mounted  on  a  small  hand  truck,  like  the  one  shown 
in  Fig.  14.  This  truck  holds  an  acetylene  cylinder  and  an  oxygen 
cylinder,  together  with  the  necessary  accessories. 

The  approximate  dimensions  and  weights  of  the  various 
types  of  generators  made  by  the  Davis-Bournonville  Co.  are 
given  in  Table  I. 

The  Buckeye  Carbide-Feeding  Mechanism.— The  phantom 
view  given  in  Fig.  15  illustrates  the  feeding  mechanism  used 
by  the  Macleod  Co.,  Cincinnati,  Ohio,  on  their  pressure  gen- 
erators. These  are  made  on  the  same  principle  as  those  just 
described,  but  this  illustration  gives  a  clearer  idea  of  the  ar- 
rangement of  the  feeding  device.  The  operating  motor  is  driven 
by  a  weight  which  is  wound  up  by  means  of  the  handle  on  top. 
The  way  the  vanes  are  set  so  as  to  sweep  the  carbide  lumps 
into  the  hole  in  the  center  of  the  bottom  of  the  hopper,  is  clearly 
shown. 

Since  commercial  demands  frequently  make  a  portable  type 
of  acetylene  pressure-generating  apparatus  desirable,  such  ap- 
paratus particularly  suited  to  the  requirements  of  large  shops, 
ship  or  railroad  yards  and  the  like,  is  made  by  several  firms.  The 
Davis  Acetylene  Co.  makes  them  in  two  sizes,  of  25-  and  50-lb. 
capacity.  These  generators  are  provided  with  a  locking  mechan- 
ism which  prevents  the  operation  of  the  feeding  mechanism 
when  the  generator  is  being  moved. 

The  Portable  Pressure  Type.— The  portable  pressure  type 
of  generator  made  by  the  Oxweld  Acetylene  Co.,  Newark,  N.  J., 
and  Chicago,  111.,  is  shown  in  Fig.  16.  These  generators  are 


ACETYLENE  AND   MEDIUM   PRESSURE  GENERATORS       37 


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38 


GAS  TORCH  AND  THERMIT  WELDING 


made  with  50-  and  100-lb.  carbide  capacity  and  respective  pro- 
ductions of  50  and  100  cu.ft.  of  acetylene,  capable  of  supplying 
3  and  6  torches.  The  50-lb.  generator  is  3  ft.  1  in.  wide,  3  ft. 
3  in.  long  and  5  ft.  8J  in.  high.  It  is  mounted  on  a  4-wheeled 
truck  4  ft.  5  in.  wide  and  7  ft.  8  in.  long,  with  an  over-all 
height  of  6  ft.  11J  in.,  and  a  weight  of  1750  Ib.  The  100-lb. 


FIG.  15. — The  Buckeye  Carbide-Feeding  Mechanism. 

size  is  mounted  on  a  truck  9  ft.  5  in.  long,  4  ft.  10  in.  wide, 
has  an  over-all  height  of  8  ft.  6  in.,  and  weighs  2300  Ib.  This 
type  of  generator  consists  of  a  single  shell  which  contains  both 
the  carbide  hopper  and  the  generating  tank.  There  is  no 
gasometer,  the  carbide-feeding  mechanism  being  controlled  by 
the  pressure  of  the  generated  gas  against  a  flexible  diaphragm. 


ACETYLENE   AND   MEDIUM   PRESSURE   GENERATORS       39 


The  feeding  mechanism  is  positive  in  action  and  is  provided 
with  an  automatic  auxiliary  no-pressure  stop  mechanism  which 
closes  the  feed  opening  in  case  the  pressure  in  the  generator 
should  be  reduced  to  zero  through  a  leak  in  the  line  or  con- 
nections or  by  reason  of  any  derangement  in  the  controlling 
device.  A  locking  handwheel  positively  locks  the  feed  mechan- 
ism in  its  closed  position  when  the  generator  is  out  of  service 


FIG.  16. — Oxweld  Portable  Pressure  Generator. 

or  when  it  is  desired  to  move  it  from  place  to  place.  This 
effectually  prevents  any  carbide  from  falling  into  the  water 
or  the  water  from  splashing  onto  the  carbide  while  the  generator 
is  being  moved.  A  complete  system  of  interference  devices 
connecting  the  filler  cap,  feed  mechanism  and  residuum  gate 
provides  against  mistakes  in  operation.  The  hydraulic  back- 
pressure valve  is  of  heavy  construction  and  is  provided  with  a 


40 


GAS   TORCH  AND   THERMIT  WELDING 


pop  valve  of  ample  size  to  carry  off  any  excess  pressure.  The 
generator  is  also  provided  with  a  diaphragm  relief  valve  of 
special  design.  The  filter  has  a  cover  which  is  interlocked  with 
the  shut-off  cock  to  prevent  the  escape  of  gas  when  the  lid  has 
been  removed  for  cleaning  purposes. 

The  construction  of  the  generator  throughout  is  of  a  heavy 
and  substantial  character.  It  may  be  mounted  on  a  4-wheel 
truck,  as  shown  in  the  engraving,  or  it  may  be  located  in  a 
stationary  position.  Space  is  provided  on  the  truck  for  three 
oxygen  cylinders  and  a  tool  chest,  making  the  entire  equipment 
self-contained. 

This  same  concern  also  makes  other  pressure  generators  in 
200-,  300-  and  500-lb.  capacities. 


Height, 

Diameter, 

Weight, 

Acetylene  Generators 

Inches 

Inches 

Lb. 

100  11)    carbide  capacity  

78 

30 

800 

200  Ib    carbide  capacity  

104 

36 

1000 

300  Ib    carbide   capacity  

115 

42 

1200 

Gisometer    100  cu  ft    capacity 

190 

76 

1500 

Height, 

Diameter, 

Weight, 

Inches 

Inches 

Lb. 

40 

16 

80 

Oil   separator           

52 

6 

200 

Purifier,  24  x  36  X  "4  inches  

800 

Compressor,  31  X  36  X  74  inches  .  , 

2500 

CHAPTER  IV 

LOW-PRESSURE   ACETYLENE   AND   THERMALENE 
GENERATORS 

The  use  of  a  low-pressure  acetylene  generator,  the  pressure 
of  which  is  limited  to  1  Ib.  or  less,  makes  it  possible  to  use  a 
gasometer  for  the  storage  of  the  generated  gas,  with  its  accom- 
panying advantage  of  absolute  volumetric  or  pressure  control. 
A  phantom  view  of  a  typical  low-pressure  generator,  made 
by  the  Oxweld  Acetylene  Co.,  is  shown  in  Fig.  17.  The 
carbide-feeding  mechanism  and  tank  closely  resemble  that  of 
the  pressure  type,  and  with  the  exception  of  the  gasometer 
and  its  mechanism,  the  rest  of  the  apparatus  resemble  it  also. 
The  possibility  of  loss  of  gas  through  ordinary  leakage  in 
the  line  and  connections  is  practically  eliminated  with  the  low- 
pressure  system.  The  gas  bell  A  provides  storage  for  gas  and 
effectively  guards  against  the  loss  due  to  after-generation. 
Control  of  the  carbide-feed  mechanism  is  accomplished  through 
the  rise  and  fall  of  the  gas  bell,  giving  a  very  constant  gas 
pressure.  The  movement  of  the  gas  bell  gives  a  dual  motor 
control,  first  through  a  carefully  adjusted  friction  brake,  which 
provides  for  gradual  starting  and  stopping,  and,  second,  through 
a  positive  jaw  clutch.  Special  provision  is  made  for  shutting 
off  the  motor  feed  when  the  gas  bell  is  in  its  lowest  position, 
which  might  result  from  a  severe  leak  in  the  line  or  connections. 
Operation  of  the  generator  is  effected  by  a  small  but  efficient 
weight-driven  motor  B,  which  is  automatically  started  and 
stopped  in  proportion  to  the  amount  of  gas  being  used.  The 
motor  weights  C  always  lower  approximately  the  same  distance 
for  each  pound  of  carbide  used,  and  constitute  a  reliable  in- 
dication of  the  amount  of  carbide  remaining  in  the  machine  at 
any  time.  The  generator  requires  no  attention  whatever  other 
than  periodic  recharging  with  carbide  and  water.  By  the  use 
of  a  positive  forced  feed,  it  is  impossible  for  more  than  the 

41 


42 


GAS  TORCH  AND  THERMIT  WELDING 


proper  quantity  of  carbide  to  be  fed  to  the  water  at  a  time. 
In  order  to  secure  cool,  and  hence  efficient,  generation,  it  is 
necessary  to  have  not  less  than  one  gallon  of  water  capacity  per 
pound  of  carbide  charge.  This  requirement  is  met  by  all  of. 
these  generators. 

A  complete  and  efficient  system  of  interlocking  safety  de- 


FILTER 


HYDRAULIC 
BACK- PRESSURE 
VALVE 


FIG.  17. — Sectional  View  of  Oxweld  Low-Pressure  Generator  Showing 
Interior  Arrangement  and  Direction  of  Flow  of  Gas. 

vices  prevents  mistakes  in  operation  due  to  carelessness  or  for- 
getfulness  when  charging  the  generator.  The  hydraulic  back- 
pressure valve  with  three  distinct  water  seals  prevents  the  pos- 
sibility of  any  oxygen  entering  the  generator. 

The  generator  is  equipped  with  an  agitator  D,  which  churns 
the  residuum  thoroughly,   allowing  it  to  flow   out   freely   and 


LOW-PRESSURE   ACETYLENE   GENERATORS 


43 


quickly  when  the  residuum  outlet  is  opened  for  recharging. 
These  low-pressure  generators  use  the  nut,  or  1$  X  8-in.  size 
carbide. 

The  Oxweld  Duplex  Generators. — The  duplex  form  of  gen- 
erator, shown  in  Fig.  18,  is  designed  to  meet  the  requirements 
of  many  industries,  where  continuous  operation  of  the  generator, 
without  interruption  for  cleaning  or  repairing,  is  essential.  It 
is  made  up  of  two  of  the  low-pressure  generators,  both  deliver- 


FlG.  18. — Oxweld  Low-Pressure   Acetylene  Generator,   Duplex  Type. 

ing  to  the  same  gasometer.  Either  generator  can  be  operated 
independent  of  the  other,  allowing  one  to  be  used  while  the 
other  is  being  recharged.  The  low-pressure  generators  are  made 
in  a  number  of  sizes,  details  of  which  are  given  in  Table  II. 

Reputable  manufacturers  always  supply  detailed  instructions 
as  to  the  care  and  maintenance  of  their  generators.  These 
should  be  posted  in  a  permanent  place  near  the  generator  and 
should  be  strictly  adhered  to  in  setting  up,  starting,  and 
refilling. 


44 


GAS  TORCH  AND   THERMIT    WELDING 


The  following  general  precautions  should  always  be  ob- 
served : 

In  charging  a  generator  never  use  anything  but  the  hands 
or  a  wooden  stick  to  poke  the  carbide,  on  account  of.  the  danger 
of  causing  a  spark. 

TABLE    II. — OXWELD  -  LOW-PRESSURE    GENERATOR    SIZES 


Carbide 
Capacity 
in 
Pounds 

Single  or 
Duplex 

Gas 
Capacity 
Cu.  Ft. 
Per 
Hour 

Approx. 
No  of 
Blow- 
pipes 

DIMENSIONS 

Appror. 
Shipping 
Weight, 
Com- 
plete 
Plant 

Min. 
Width 
of  Door 
Through 
Which 
Gen.  will 

Height 

Length 

Width 

Pass 

50 

Single  ,  

50 

3 

7'  4" 

5'    7" 

3'  2" 

1400 

29K" 

50 

Duplex  

50 

3 

7'  4" 

8'  10" 

3'  2" 

1800 

29W 

100 

Single  

100 

6 

7'6' 

6'    2" 

3'  7" 

1900 

33" 

100 

Duplex  

100 

6 

7'  6' 

9'    8" 

3'  7" 

2400 

33' 

200 

single  

200 

12 

9'  4' 

8'    0" 

5'0" 

2500 

41" 

200 

Duplex  

200 

12 

9'  4' 

13'   0" 

y  0" 

3500 

41" 

300 

single  

300 

18 

10'  1' 

-8'  10" 

5'  4" 

4100 

48" 

300 

Duplex  

300 

18 

10'  T 

14'    1" 

5'  4" 

4800 

48" 

500 

Single  

500 

10 

11'  7' 

11'    3" 

6'  6" 

4800 

62" 

500 

Duplex  

500 

30 

11'7" 

18'    0" 

6'  6" 

6500 

62" 

As  far  as  practicable  do  all  charging,  cleaning,  adjusting, 
and  manipulating  of  the  generator  by  daylight. 

Avoid  as  far  as  possible  the  introducing  of  air  into  the 
generator,  or  the  circulation  of  air  through  it.  Never  leave  any 
opening  in  the  machine  open  longer  than  is  necessary  and  never 
have  any  two  openings,  such  as  the  carbide  charging  door  and 
the  sludge  valve,  open  at  the  same  time. 

Keep  the  generator  full  of  water  at  all  times,  even  when 
not  in  use.  When  the  sludge  is  drawn  off  and  the  machine 
flushed  out,  do  not  do  anything  else  until  it  has  been  refilled 
as  directed  in  the  instructions  for  recharging  it. 

Never  open  the  carbide  filling  plug,  charge  the  machine  with 
carbide,  do  any  adjusting  or  manipulating,  or  make  repairs, 
unless  the  generating  chamber  is  full  of  water,  as  directed  in 
the  instructions  for  operating  the  generator. 

Kenew  the  water  in  the  generating  chamber  each  time  any 
carbide  is  placed  in  the  hopper.  Never  run  more  than  one 
charge  of  carbide  into  the  generating  chamber  without  refilling 
with  fresh  water.  Do  not  experiment. 

If  water  in  any  chamber  of  the  generator  should  freeze,  do 
not  attempt  to  thaw  it  with  anything  but  hot  water;  and  then 
examine  the  generator  carefully  for  any  damage  which  freezing 
may  have  caused. 


LOW-PRESSURE   ACETYLENE   GENERATORS  45 

If  the  generator  should  ever  require  repair:  First,  remove, 
all  carbide;  second,  drain  all  water  from  the  generating 
chamber,  then  refill  the  generating  chamber  as  if  for  recharg- 
ing; third,  disconnect  the  generator  from  piping  and  remove 
it  to  the  open  air,  then  fill  all  the  compartments  with  water 
and  thus  force  out  all  mixtures  of  gas  and  air  before  applying 
soldering  irons  or  any  tools  that  could  cause  a  spark.  See  that 
the  workmen  removing  or  repairing  the  generator  understand 
this  thoroughly. 

Familiarize  yourself  thoroughly  with  the  directions  for 
operating  your  generator,  which  are  furnished  by  its  makers; 
and  when  recharging  the  machine  follow  them  in  the  order  in 
which  they  are  given. 

Thermalene  Generators. — In  composition  and  method  of  pro- 
duction, thermalene  differs  from  any  gas  previously  used  for 
welding  purposes.  It  is  a  combination  produced  by  the  de- 
composition of  calcium  carbide  and  hydrocarbon  oil,  the  heat 
generated  by  the  carbide  being  used  to  vaporize  the  oil.  It  is 
the  discovery  of  Karl  Friedrich  Linus  Wolf,  of  Zurich,  Switzer- 
land, and  is  handled  in  this  country  by  the  Thermalene  Co., 
Chicago  Heights,  111. 

Thermalene  generation  is  a  very  unique  proposition  and 
was  first  fully  described  in  the  "American  Machinist,"  Aug. 
10,  1916.  At  present  thermalene  is  principally  used  for  welding 
or  cutting  metals,  in  which  it  is  used  together  with  the  proper 
mixture  of  oxygen.  The  nature  of  the  gas  will  be  better  un- 
derstood by  first  giving  a  description  of  the  method  by  which 
it  is  produced. 

A  phantom  view  of  a  generator  is  shown  in  Fig.  19.  To 
prepare  this  generator  for  operation,  water  is  poured  in  through 
funnel  A  until  it  will  run  out  of  pet-cock  B,  which  fills  the 
casing  about  two-thirds  full.  The  generating  mixture  is  carried 
in  a  tin  can  or  cartridge  that  is  inserted  from  the  bottom  into 
the  cartridge  chamber,  as  shown  at  C.  Previous  to  inserting 
the  cartridge,  however,  care  is  taken  to  pull  down  the  cam  lever 
Z>,  which  pulls  up  the  rod  and  closes  the  water  valve  E.  This 
prevents  any  water  entering  the  cartridge  chamber.  After  the 
cartridge  has  been  inserted  through  the  door  in  the  bottom  of 
the  chamber,  the  door  is  closed  and  the  bar  F  brought  up  and 
locked  by  means  of  the  handwheel  G.  To  generate  gas  the  cam 


46 


GAS   TORCH   AND   THERMIT  WELDING 


lever  on  top  is  pulled  up  as  far  as  it  will  go.  This  admits 
water  from  the  water  chamber  H  into  the  cartridge  chamber 
through  the  center  tube  to  the  bottom  of  the  cartridge,  from 
where  it  begins  to  work  upward. 

How  the  Cartridge  Is  Packed. — The  cartridge  is  packed  with 


FIG.  19. — Phantom  View  of  Thermalene  Generator. 

alternate  layers  of  calcium  carbide  and  crude  oil  mixed  with 
sawdust.  The  water  as  it  rises  slacks  the  carbide  and  generates 
acetylene  gas.  The  heat  caused  by  the  slacking  of  the  carbide 
layer  vaporizes  the  oil  in  the  layer  of  mixed  oil  and  sawdust 
immediately  above  the  layer  of  slacking  carbide  and  generates 


LOW-PRESSURE   ACETYLENE   GENERATORS  47 

oil-gas.  When  the  gas  pressure  as  indicated  by  the  gage  is  up 
to  5  lb.,  the  valve  J  is  opened,  which  lets  the  gas  enter  the 
hose  leading  to  the  storage  tank  or  torch.  The  pet-cock  at  K 
is  used  to  drain  off  the  impurities,  such  as  phosphor-hydrogen 
or  ammonia,  which  have  been  separated  from  the  carbide  gas 
in  the  process  of  generation.  At  L  is  a  check  valve,  which  allows 
gas  to  escape  from  the  cartridge  chamber,  but  effectually  pre- 
vents any  return  of  either  gas  or  water.  As  soon  as  a  cartridge 
is  exhausted  it  is  easily  removed,  carrying  all  of  the  dirt  and 
sludge  with  it. 

With  the  use  of  a  storage  tank,  enough  gas  is  carried  to  run 
a  torch  while  a  new  cartridge  is  being  put  in  place  in  the 
generator,  if  needed.  The  pressure  limit  for  welding  or  cutting 
is  15  lb.  When  this  pressure  is  reached,  a  regulating  diaphragm 
at  M  automatically  cuts  off  the  water  feed  and  stops  the  genera- 
tion of  gas.  This  diaphragm  is  placed  at  the  top  of  the  generator, 
on  the  inside,  where  the  gas  pressure  acts  directly  on  it.  The 
diaphragm  is  connected  to  the  feed-valve  rod  in  the  center,  so 
that  as  the  diaphragm  is  forced  upward  by  the  gas  pressure, 
the  water  valve  is  partly  or  wholly  closed.  It  is  so  arranged 
as  to  be  easily  set  for  various  desired  pressures. 

As  previously  stated,  the  cartridges  are  made  up  of  alternate 
layers  of  calcium  carbide  and  oil-soaked  sawdust.  Now  it  is 
well  known  that  the  volume  of  lime  into  which  calcium  carbide 
is  converted  by  the  slacking  process  is  greater  than  the  volume 
of  the  carbide.  Therefore,  when  carbide  is  packed  tightly  in 
cartridges,  as  desirable,  the  expansion  is  liable  to  burst  the 
case,  and  in  some  instances  might  cause  the  cartridge  to  jam 
in  the  chamber,  as  well  as  interfere  with  the  successful  working. 
One  of  the  objects  then  is  to  so  make  the  cartridge  as  to  allow  for 
the  expansion  of  the  contents.  Another  is  to  prevent  the  oil 
from  coming  in  contact  with  the  carbide,  as  this  would  interfere 
with  the  action  and  decrease  the  gas  output.  To  summarize, 
the  cartridge  components  must  be  so  arranged  as  to  promote 
free  action  of  the  carbide ;  free  action  of  the  heat  evolved  from 
the  carbide  on  the  volatile  substance;  to  prevent  action  of 
moisture  on  the  carbide  layers  not  being  acted  upon  purposely ; 
and  to  promote  the  free  discharge  of  the  generated  and  volatilized 
gases. 

All  of  these  points,  as  well  as  a  number  of  others,  have 


48 


GAS   TORCH  AND  THERMIT  WELDING 


been  considered  in  the  makeup  of  the  cartridges,  as  shown  in 
detail  in  Fig.  20.  As  made  at  present  for  commercial  purposes, 
there  are  four  sizes  corresponding  to  the  different  outfits.  The 
cartridges  consist  of  a  tin  can  of  suitable  size,  the  smallest 
being  4f  in.  in  diameter  and  8  in.  high,  weighing  6  Ib.  and 
having  a  gas-producing  capacity  of  25  cu.ft.,  sufficient  to  supply 
a  welding  torch  from  four  to  five  hours.  The  largest  size  is 
9J  in.  in  diameter  and  16  in.  high,  weighing  40  Ib.  This  has 


FIG.  20. — Details  of  Thermalene  Cartridge. 

a  gas  production  of  200  cu.ft,  or  eight  times  the  capacity  of 
the  smallest  size  which  has  been  previously  mentioned. 

Referring  now  to  the  illustration,  a  cylindrical  screen  A  is 
first  placed  in  the  can  to  be  filled  and  then  a  layer  of  carbide 
is  placed  in  the  bottom  of  the  can  around  the  screen  tube.  An 
unglazed  carboard  disk  B  is  next  placed  on  top  of  the  carbide. 
A  spacer  C,  mad-e  of  thin  metal  bent  so  as  to  lie  edgewise,  is 
placed  on  top  of  the  cardboard  and  then  a  disk  of  screen  is  put 
over  it.  Sawdust  impregnated  with  crude  oil  in  a  cloth  sack 
made  of  two  cloth  disks  sewed  together  is  laid  on  the  screen. 


LOW-PRESSURE    ACETYLENE   GENERATORS  49 

On  this  is  another  screen,  then  a  spacer  and  a  cardboard  disk, 
and  so  on  to  the  top,  ending  with  a  sack  of  oil,  soaked  sawdust 
covered  with  a  piece  of  screen  that  has  no  hole  in  the  center 
for  the  cylindrical  tube.  The  end  of  the  can  is  closed  with  a 
cover  for  handling,  which  is  removed  before  placing  in  a 
generator. 

As  previously  mentioned,  the  water  feeding  in  through  the 
valve  in  the  cartridge  chamber  drips  down  through  the  cylin- 
drical screen  tube  and  starts  slacking  of  the  lower  layer  of 
carbide,  the  heat  of  which  vaporizes  the  oil  in  the  sack  above 
it.  The  cardboard  disks,  while  strong  enough  to  hold  the  layers 
firmly  in  place  while  dry,  begin  to  soak  up  as  soon  as  the 
feeding  starts,  and  consequently  become  soft,  so  as  to  give  way 
under  the  pressure  of  the  expanding  carbide,  allowing  it  to  be 
forced  into  the  spacing  between  the  carbide  and  the  oily  saw- 
dust. This  space  is  so  calculated  as  to  keep  the  various  layers 
firmly  in  place  until  the  cartridge  is  exhausted.  Another  thing 
is  that,  as  any  liberated  steam  or  water  vapor  must  pass  through 
the  absorbent  cardboard  as  well  as  the  oil,  before  it  reaches  the 
next  layer  of  carbide,  action  of  the  steam  on  the  carbide  above 
is  prevented.  This  insures  that  the  respective  layers  of  carbide 
will  not  be  acted  upon  until  the  water  becomes  level  with  them 
in  turn.  In  consequence,  a  cartridge  can  remain  in  a  generator 
a  long  time  without  becoming  spent.  The  screen  disks  on  top 
and  bottom  of  each  layer  of  oily  sawdust  furnish  efficient 
volatilization  and  egress  for  the  gas. 

By  the  method  of  producing  thermalene,  the  heat  evolved 
by  the  generation  of  acetylene  is  absorbed,  at  the  place  of 
generation,  in  the  production  of  the  oil  gas.  This  utilization 
of  heat  serves  to  keep  the  temperature  down,  since  the  heat 
generated  is  used  and  dissipated  by  the  latent  heat  of  the  oil, 
so  that  radiation  and  absorption  by  water  is  not  necessarily 
depended  upon.  The  gas  combination  that  results  passes  out 
through  the  T-pipe  ends  and  bubbles  up  through  the  water  into 
the  upper  part  of  the  generator.  The  low  temperature  causes 
the  impurities  to  drain  back  into  the  chamber,  from  which  they 
are  easily  removed.  The  layers  of  carbide  and  oily  sawdust 
are  so  proportioned  as  to  cause  only  the  vaporization  of  the 
lighter  oils,  such  as  benzine,  naphthalene,  kerosene  and  the  like. 
The  temperature  is  not  high  enough  to  vaporize  the  tar  oils, 


50  GAS   TORCH   AND   THERMIT   WELDING 

as  these  are  heavy  and  give  a  deposit  of  lampblack.  These 
heavy  oils  are  therefore  not  utilized,  but  remain  in  the  cartridge. 
The  temperature  in  the  cartridge  is  maintained  between  200 
and  300  deg.  C.  (392  to  572  cleg.  F.),  depending  upon  the 
rapidity  with  which  the  gas  is  being  used  and  the  amount  which 
is  generated  and  delivered.  It  is  not  intended  that  an  actual 
boiling  take  place  at  any  time,  for  if  the  temperature  is  too 
high  there  will  be  a  vaporization  of  the  heavy  oils,  causing  de- 
posits in  the  pipes  and  also  an  increase  in  the  impurities.  The 
gases  passing  through  the  pipes  cooled  by  the  water  of  the 
generator  are  kept  between  60  and  70  deg.  F.  In  the  passage 
through  the  cooled  pipes  the  impurities  are  removed  in  the 
following  manner:  Acetylene  has  a  comparatively  high  specific 
heat,  so  that  its  rate  of  cooling  when  passing  through  the  pipes 
is  low.  The  specific  heat  of  oil  gas  is,  however,  only  one-eighth 
of  that  of  acetylene,  so  that  its  cooling  effect  will  be  eight  times 
as  great.  Now  if  the  two  gases  are  passed  together  along  a 
cooling  surface,  the  temperature  of  low  specific  heat  will  de- 
crease rapidly  and  cause  a  rapid  lowering  of  the  temperature 
of  the  other  gas.  This  causes  a  deposit  of  the  vapors  suspended 
therein.  So  this  action  results  in  the  deposit  of  the  sulphur, 
phosphorus  and  silicon  compounds,  and  of  the  ammonia.  In 
order,  however  to  bring  about  this  precipitation  the  temperature 
must  be  sufficiently  low — that  is,  as  stated  above,  between  60 
and  70  deg.  F.  If  the  gas  finally  issuing  from  the  pipes  and 
water  was  too  hot,  the  impurities  would  not  be  thrown  out. 

In  this  process  the  acetylene  and  oil  gas,  generated  and 
cooled,  will  combine  in  the  pipes  after  the  impurities  are  re- 
moved. It  is  important,  however,  that  the  impurities  be  removed 
and  the  product  sufficiently  cooled,  since  no  real  combination 
will  take  place  at  too  high  a  temperature.  For  instance,  if  the 
water  is  above  180  deg.  F.  the  oil  burns  and  no  proper  com 
bination  results. 

The  combined  gas  produced,  named  thermalene,  possesses 
marked  characteristics  that  distinguish  it  from  oil-gas,  from 
acetylene,  and  from  the  usual  mixture  of  the  two.  The  density 
is  greater  than  air,  being  1.1  taking  air  as  unity.  The  issuing 
gas  can  be  seen  to  sink  when  thrown  through  a  sunbeam.  The 
specific  heat  is  low,  being  a  little  over  one-eighth  of  that  of 
acetylene.  Thermalene  liquefies  at  between  1400-  and  1500-lb. 


LOW-PRESSURE   ACETYLENE   GENERATORS          51 


pressure  per  square  inch  at  room  temperature,  and  in  its  liquid 
state  is  nonexplosive  and  stable.  A  very  noticeable  thing  is  the 
odor,  which  is  not  at  all  like  the  odor  of  either  acetylene  or 
of  oil-gas,  but  is  a  soft,  sweet  smell,  not  strong  or  offensive  in 
any  way.  The  color  is  white,  but  with  a  predominating  pro- 
portion of  the  red  and  yellow  parts  of  the  spectrum.  The 


FIG.  21. — Thermalene  Outfit  for  Shop  "Use. 

maximum  flame  temperature,  according  to  H.  McCormack,  pro- 
fessor of  chemical  engineering,  Armour  Institute  of  Technology, 
Chicago,  111.,  has  been  found  to  be  about  6500  deg.  F.  The  high 
density  of  the  gas  has  a  number  of  advantages.  It  has  more 
body  than  acetylene  and  does  not  need  so  much  oxygen.  More- 
over, it  mixes  better  with  oxygen.  It  does  not  explode  as 


52  GAS  TORCH  AND  THERMIT  WELDING 

readily  as  acetylene,  so  can  be  mixed  with  greater  proportions 
of  an/.  In  a  Bunsen  burner  it  is  possible  to  mix  as  much  as 
32  per  cent  of  air  without  causing  a  flareback.  It  can  readily 
be  turned  down  without  causing  a  flareback,  and  it  can  be  used 
with  a  Welsbach  mantle  to  advantage.  The  upper  and  lower 
explosive  limits  are  12  per  cent  and  30  per  cent.  It  averages 
approximately  13.97  cu.ft.  per  pound. 

Some  Advantages  of  Thermalene. — When  used  for  welding 
and  cutting,  thermalene  has  numerous  good  points.     It  does  not 


FIG.  22.— Portable  Thermalene  Generator  Outfit. 

require  an  excess  of  oxygen,  and  the  flame,  therefore,  produces 
a  soft  weld,  especially  in  cast  iron.  When  welding  it  is  notice- 
able that  less  sparks  are  thrown  off  than  when  using  acetylene. 
It  can  be  used  at  a  lower  pressure  also,  owing  to  its  greater 
calorific  value.  Owing  to  the  removal  of  the  various  impurities, 
there  are  no  corrosive  effects  on  fittings,  nor  poisonous  effects. 
It  is  also  for  this  reason  that  there  is  little  or  no  danger  of 
explosion.  Neither  does  the  spent  cartridge  give  off  explosive 
gases,  for  the  reason  that  the  gases  liable  to  cause  explosion  are 
separated  and  drained  off  from  the  generator  chamber.  Cor- 


LOW-PRESSURE  ACETYLENE   GENERATORS  53 

rosion  of  interior  walls,  due  to  water  action,  is  prevented  by  the 
oil  vapor  which  is  always  present  and  forms  a  protecting  and 
sealing  effect  throughout.  , 

A  thermalene  generator  may  discharge  its  gas  into  a  storage 
tank,  or  the  gas  may  be  used  direct  from  generator  to  torch.  A 
welding  or  cutting  outfit,  suitable  for  shop  use,  where  it  will 
not  need  to  be  moved  frequently,  is  shown  in  Fig.  21.  Here 
the  gas  is  used  direct  from  generator  to  torch.  The  smallest 
generator  like  the  one  shown  is  10^  in.  in  diameter,  stands  3  ft. 
9  in.  high,  and  weighs  about  60  Ib.  An  apparatus  mounted  on 
a  truck  is  shown  in  Fig.  22.  As  a  rule  a  No.  2  generator  is 
used  for  this  purpose.  This  size  is  16  in.  in  diameter,  stands 
6  ft.  high,  and  will  produce  70  cu.ft.  of  gas  with  one  charge, 
the  generator  weighing  225  Ib.  and  the  storage  tank  120  Ib. 
The  largest  size  generators  will  produce  200  cu.ft.  of  gas  per 
charge,  and  they  may  be  coupled  in  batteries  where  a  large 
amount  of  gas  is  desired.  These  can  be  arranged  so  that  part 
of  them  can  be  recharged  while  the  others  are  working,  or 
storage  tanks  of  sufficient  capacity  may  be  used  to  allow  for 
recharging, 


CHAPTER  V 
GAS  TORCHES  USED  FOR  WELDING 

The  gas  torches  used  for  welding  in  the  United  States  may 
be  divided  into  two  general  types,  known  as  medium-pressure 
and  low-pressure  torches.  Each  type  is  made  in  a  number  of 
sizes,  and  each  size  is  usually  provided  \vith  a  number  of  in- 
terchangeable tips  for  producing  flames  of  different  size. 

The  medium  pressure  torches  are  also  known  as  positive- 
pressure  torches,  and  to  avoid  misunderstanding,  they  will  be 
referred  to  as  positive-pressure  torches  hereafter.  In  these 
torches,  using  acetylene  and  oxygen  for  welding,  the  acetylene 
pressure  will  range  from  1 .  to  14  Ib.  and  the  oxygen  pressure 
from  1  to  24  Ib.  per  square  inch,  the  pressure  employed  de- 
pending on  the  thickness  of  the  metal  being  welded,  the  make  of 
torch,  and  the  tips  used.  The  pressures  given  may  even  be 
exceeded  in  some  exceptional  cases. 

A  sectional  view  of  a  typical  positive-pressure  welding  head 
is  shown  in  Fig.  23.  The  oxygen  enters  at  A  and  the  acetylene 
enters  at  B.  The  oxygen  goes  to  the  small  chamber  C  and 
thence  out  through  the  center  hole.  The  acetylene  goes  to  the 
chamber  D  and  also  out  through  the  center  hole,  the  two  gases 
starting  to  mix  at  the  point  E,  and  as  they  pass  out  through 
the  channel  F  to  the  end  of  the  tip,  they  are  thoroughly  mixed. 
In  this  illustration,  the  removable  tip  is  indicated  by  G.  This 
make  of  tip  has  a  conical  seat  and  held  in  its  place  by  means 
of  the  lock  collar  H.  Made  in  this  way,  there  are  no  threads 
on  the  tip  itself,  although  the  practice  varies  in  different  makes. 

The  low-pressure  torch  is  also  known  as  the  injector  type. 
In  this  type  of  torch,  the  acetylene,  or  other  gas,  is  supplied 
under  a  pressure  of  a  few  ounces  up  to  1  Ib.,  but  the  oxygen 
may  have  a  pressure  of  from  5  to  30  Ib.  per  square  inch,  accord- 
ing to  the  size  of  tip  being  used.  In  some  cases  the  oxygen 
pressure  may  be  either  higher  or  lower  than  the  figures  given, 

54 


GAS  TORCHES  USED  FOR  WELDING 


55 


A  sectional  view  of  a  typical  low-pressure  torch  is  shown  in 
Fig.  24.  In  this  torch  the  acetylene,  or  other  gas,  enters  at  A 
and  the  oxygen  at  B.  The  acetylene  goes  to  the  chamber  C 
from  which  it  is  sucked  by  the  oxygen  pouring  out  through 
the  nozzle  at  D,  and  it  is  carried  along  with  the  oxygen  into 
the  mixing  chamber  E  in  the  tip  of  the  torch.  From  this 
chamber  the  gases  issue  thoroughly  mixed  and  ready  for  com- 
bustion. 

As  they  qualify  for  classification  as  either  positive-pressure 


FIGS.  23  and  24. — A  Typical  Positive-Pressure  Welding  Torch  and  a  Low- 
Pressure  or  Injector  Type  of  Welding  Torch. 

or  low-pressure  types  of  torches,  the  various  makes  of  each  type 
differ  principally  in  form,  the  general  principles  of  action 
remaining  the  same.  A  few  examples  of  the  different  makes 
of  positive-pressure  torches  will  be  shown  first,  and  these  will 
be  followed  by  others  of  the  low-pressure  or  injector  type. 

A  standard  form  of  a  positive-pressure  welding  torch,  made 
by  the  Davis-Bournonville  Co.,  is  shown  in  Fig.  25  and  in  detail 
in  Fig.  26.  A  number  of  torches  used  for  various  purposes  are 
shown  in  Fig.  27.  In  this  illustration,  A  is  a  small  lead-burning 
torch.  5  is  a  midget  torch  used  for  welding  very  light  sheet 


56 


GAS  TORCH  AND   THERMIT  WELDING 


metal  for  manufacturing  purposes,  such  as  the  seams  of  cooking 
utensils,  aluminum  ware,  etc.  It  weighs  about  8  oz.,  is  10  in. 
long,  and  may  be  used  on  sheets  up  to  £  in.  thick.  C  is  a  small- 
size  torch  for  metal  from  1/32  to  5/16  in.  thick,  weighs  18  oz.,  is 
14  in.  long  and  uses  oxygen  pressures,  with  different  tips,  of 


FIG.  25. — The  Davis-Bournonville  Style  C  Positive-Pressure  Welding  Torch. 


Carbureting  device  which  positively  and 
(intimately  mixes  the  two  gases  in  proper  proportion 

^•^  s\\s\ss- r- At 


Oxygen  needle 


Conica/\ 

Ground  A 


.OXYGEN 


ACETYLENE 

'^The  two  gases  strike 
together  at  right  angles 
creating  a  vortex  which 
insures  intimate  mixture 

The  diameters  of  the  parts  in  the  carbureting  device 
are  proportioned  to  each  size  of  tip,  to  deliver  proper 
volumes  of  gas  for  each  size  of  flame  produced. 

^Luminous  Cone  of  Flame 

Secondary  reaction.  Hydrogen  and  carben 
monoxide  burn,  taking  the  necessary  oxygen 
from  the  air  and  produce  water  vapor  ana 
carbon  dioxJde. 


Acetylene  needle- 
Valve 


FIG.  26 Details  of  the  Davis-Bournonville  Welding  Torch. 

from  2  to  10  Ib.  D  is  a  manufacturer's  torch,  intended  for 
use  on  boilers,  steel  barrels,  metallic  caskets,  tanks,  cylinders, 
etc.  The  head  is  set  at  right  angles  to  the  body,  which  has  been 
found  best  for  this  work.  It  weighs  24  oz.,  is  18  in.  long  and 
uses  oxygen  at  2  to  10  Ib.  pressure,  according  to  the  tips  em- 
ployed. E  is  a  large  torch  for  heavy  welding.  It  weighs  2  Ib., 


GAS   TORCHES   USED   FOR  WELDING 


57 


is  20  in.  long,  and  uses  oxygen  at  12  to  20  Ib.  pressure.  It  is 
used  on  metal  from  \  in.  thick  up.  F  is  a  water-cooled  torch, 
used  for  heavy  welding  where  the  tips  have  a  tendency  to  be- 
come overheated.  It  is  36  in.  long  and  weighs  about  3J  Ib. 
Four  lines  of  hose  are  needed  with  it,  two  for  water  and  two 


FIG.  27. — Various  Models  of  Davis-Bournonville  Welding  Torches. 


for  gas.  G  is  used  for  welding  with  oxygen  and  hydrogen.  H 
is  for  use  on  a  welding  machine.  /  is  a  water-cooled  torch  for  a 
welding  machine.  J  is  water-cooled,  for  machine  use  and  has 
a  multiple-jet  nozzle  or  tip.  All  of  the  torches  mentioned  are 
furnished  with  five  interchangeable  tips  for  different  thick- 


58 


GAS  TORCH  AND   THERMIT  WELDING 


nesses  of  metal.  These  tips,  however,  do  not  fit  torches  of 
different  size;  that  is,  the  tips  for  large  torches  will  not  fit 
small  ones,  nor  vice  versa.  All  the  torches  named  are  intended 
for  oxygen  and  acetylene,  except  where  mentioned  otherwise. 
A  number  of  different  tips  designed  to  be  used  with  the  torches 
illustrated,  are  shown  in  Fig.  28. 

The  approximate  pressures  of  oxygen  and  acetylene  as  used 
in  the  Davis  torches  are  given  in  Table  III.  The  tips  referred 
to  in  compiling  this  table  are  known  as  styles  Nos.  99  and  100, 


SMALL  STVLF. 
A&B  TIPS 


LARGE  STYLE 
A&B  TIPS 


STYLE    B 


EXTRA  LARGE 
MULTIPLE  FLAME 


LEAD  BURNING 
TIPS 


EXTRA  LARGE 
WATER  COOLED 


\ 


FORCI"*  3AS 


MULTIPLE  FLAHE 


PENCIL  TORCH 
WELD  TIP 


5MALL"C"TlP 
FOR  CITY  GAS 


<=  —  Olfn 


WATER  COOLED 
HAND  WELD  TIP 


FOR  HAND 
WELDING 


THREE  PIECE 
TIPSMALL"C" 


WATER  COOLED 
MACH.WELD  TIP 


FOR  MACHINE 
WELDING 


THREE  PIECE 
TIPSMALL"C" 


O)D 


SMALL  "C 
EDISON  WELD 


OXY-HYDRIC 
WELD  TIP 


LLUMINATING 
GAS  TIP 


FOR  MELTING  i 
PLATINUM 


OXY.-ACET 
WELD  TIP 


7"  LONG 


COPPER  POINT 
WATER  COOLED 


CHICAGO  STYLE 


LAR 
C 


L--.RGE  UC" 
WATER  COOLED 


a       o 


PREHEATING 
TIP 


FIG.  28. — Different  Kinds  of   Tips  Used  with  Davis-Bournonville 
Welding  Torches. 

and  are  used  with  style  C  torches.  These  pressures  serve  only 
as  approximate  guides  and  are  not  to  be  taken  literally  in 
practice. 

The  Prest-0-Lite  Torch. — The  torch  shown  in  detail  in 
Fig.  29  is  made  by  the  Prest-O-Lite  Co.,  Indianapolis,  Ind., 
but  is  handled  by  the  Oxweld  Acetylene  Co.  This  torch  is 
fitted  with  a  long  stem  through  which  the  gases  pass  and  are 
thoroughly  mixed  before  issuing  from  the  nozzle. 

The  stem  is  fitted  to  the  mixing  chamber  by  means  of  a 
union  nut,  which  permits  the  operator  to  point  the  welding 
tip  in  any  direction,  without  changing  his  method  of  holding 


GAS  TORCHES   USED   FOK  WELDING 


59 


the  torch.  This  is  particularly  advantageous  for  vertical  and 
overhead  welding.  Both  oxygen  and  acetylene  inlets  on  the 
torch  are  fitted  with  fine-adjustment  control  valves.  The  one 
on  the  oxygen  supply  is  so  placed  that  the  operator  while 
working  can  make  any  slight  necessary  adjustment  with  the 
forefinger  of  the  hand  that  grips  the  torch.  The  handle  of 
the  torch  is  fitted  with  anti-fireback  chambers  for  both  gases, 
filled  with  a  special  material  through  which  it  is  impossible 

for  a  flame  to  pass. 

r\  • 

TABLE    III. — APPROXIMATE    GAS    PRESSURES    FOR    DAVIS-BOURNONVILLE 
STYLE  C  WELDING  TORCH,  WITH  Nos.  99  AND  100  TIPS 


Tip 
No. 

Thickness 
of  Metal 
Inches 

Acetylene 
Pressure 
Lbs, 

Oxygen 
Pressure 
Lbs. 

00 

/  Very  \ 

1 

1 

C 

\LightJ 

1 

2 

1 

T5~/l6 

1 

2 

2 

Jl6~~A 

2 

4 

3 

J±—  l/£ 

3 

6 

4 

%~% 

4 

8 

5 

%T%> 

5 

10 

6 

%T% 

6 

12 

7 

%r% 

6 

14 

8 

x^~5^ 

6 

16 

9 

^"~M 

6 

18 

10 

J^-Up 

6 

20 

11 

f  Extral 

8 

22 

12 

\Heavyj 

8 

24 

The  torch  is  easy  to  dismantle,  as  all  parts  are  screwed 
together  on  metal-to-metal  seats  and  no  packing  or  solder  is 
used  at  any  joint. 

For  extra  heavy  work,  a  special  stem  22  in.  long  is  fur- 
nished, and  for  close  work  a  5J-in.  stem  may  be  had  in  addi- 
tion to  the  regular  size.  The  regular  stem  has  seven  tips, 
the  largest  four  being  of  copper  which  will  stand  up  against 
the  intense  heat  radiated  from  the  work  better  than  any 
other  metal.  The  smaller  tips  are  of  a  special  alloy.  A 
similar  torch  is  also  made  for  very  light  work  which  weighs 
only  3  oz.  complete. 

In  the  detailed  view  given  of  the  torch,  A  is  the  hose  nipple 


60 


GAS   TORCH  AND   THERMIT  WELDING 


through  which  the  oxygen  passes.  At  B  is  a  set  of  40  strainer 
cloths  for  the  oxygen  filter  chamber;  C  is  the  oxygen  needle 
valve;  D  is  the  acetylene  hose  nipple;  E  is  the  acetylene 


Complete  Oxygen 
Valve  Assembl 


40  Pieces 


ne 


Com  pie  -f-e  'A  cefylen 
Va/ve  Assembly 


FIG.  29.— Details  of  Presto-O-Lite  Type  H  Welding  Torch. 

; & 


FIG.  30. — Torches  Made  by  the  General  Welding  &  Equipment  Co. 

flxygen    Tube 


F  F 

FIG.  31. — Details  of  Torch  Shown  in  Fig.  30. 

needle  valve;  F  is  the  acetylene  filter-chamber  cartridge;  G  is 
the  stem.  The  seven  tips  are  indicated  from  IH  to  7H,  and 
their  openings  can  be  determined  from  Table  IV.  This  table 
is  especially  valuable  in  that  the  nozzle  openings  are  shown  in 


GAS   TORCHES   USED   FOR   WELDING 


61 


regular  twist-drill  sizes,  furnishing  an  easy  method  of  com- 
parison. The  two  tips  given  at  the  bottom  of  the  table  are 
extras,  used  for  heavy  work.  The  figures  quoted  in  the  table 
are  based  on  straight  work  on  steel  plate,  beveled  when  over 
^  in.  in  thickness  and  welded  without  preheating. 

TABLE  IV. — APPROXIMATE  WELDING  RESULTS  WITH  TYPE  H,  PRESTO-O- 

LITE  TORCH 


& 

Tip 
Drill 
Size 

Gas  consumption 
Cu.  Ft.  per  hour 

Thickness  of 
Metal 

Blow-pipe  pressures 
Lps.  per  sq.  in. 

Lineal  feet 
welded 
per  hour 

Oxygen 

Acetylene 

Oxygen 

Acetylene 

1H 

69 

3  to  4 

3  to  4 

&  to  ,.3.(  in. 

2  to  3 

2  to  3 

30  to  35 

2H 

60 

6io*i 

6  to  8 

T'O  to  ai  «n- 

2  to  3 

2  to  3 

24  to  32 

3H 

55 

10  to  121 

10  to  12 

I  to  f«  in 

3  to  4* 

3  to  4 

12  to  16 
9  to  12 
6  to  8 

4H 

52 

12  to  21 

12  to  20 

t\  to  S7j  in. 

4  to  6 

4  to  5 

5H 

49 

18  to  28 

18  to  26 

J  to  ,56  in 

5  to  7 

5  to  6 

6H 

44 

24  to  40 

24  to  38 

I  to  T74  in. 

8  to  11 

8  to  9 

41  to  6 

7H 

35 

35  to  54 

35  to  50 

].  in.  and  up 

10  to  15 

10  to  14 

2  to  3 

•7J 

35 

35  to  54 

35  to  50 

?,  in.  and  up 

9  to  13 

9  to  12 

Not  used 
on  plates 

*8J 

31 

40  to  60 

40  to  55 

I  in.  and  up 

9  to  14 

9  to  13 

Not  used 
on  plates 

The  General  Welding  Co.'s  Torch. — A  welding  torch  made 
by  the  General  Welding  and  Equipment  Co.,  Boston,  Mass.,  is 
shown  in  Fig.  30.  Each  torch  is  furnished  with  nine  tips, 
affording  a  range  equal  to  all  ordinary  welding  jobs.  In  addi- 
tion, stems  of  different  lengths  may  be  had.  In  the  illustra- 
tion, A  is  the  body  of  the  torch;  B  is  the  mixing  chamber;  C 
is  a  short  stem,  the  use  of  which  makes  the  entire  torch  16  in. 
long ; '  D  is  a  medium  stem,  making  the  torch  22  in.  long ;  E  is 
a  long  stem,  making  the  total  length  of  the  torch  30  in. 

Details  of  this  torch  are  shown  in  Fig.  31.  Here  the  acetylene 
inlet  is  shown  at  A  and  the  oxygen  inlet  at  B.  The  body  of 
the  torch  is  indicated  by  C,  and  D  is  the  mixing  chamber;  E  is 
the  stem,  and  F  various  shapes  of  tips. 

Imperial  Torches. — Another  long-stemmed  torch  is  shown 


62  CAS   TORCH  AND   THERMIT  WELDING 

in  Fig.  32.  This  is  made  by  the  Imperial  Brass  Manufacturing 
Co.,  Chicago,  and  differs  but  little  from  the  one  just  shown. 
The  gas  valves,  however  are  placed  at  the  forward  end  of  the 
body.  Like  most  of  the  other  torches,  these  may  be  used  not 
only  for  oxy-acetylene,  but  also  for  oxy-hydrogen  welding  work, 
special  tips  and  regulators  being  made  for  the  purpose.  For 
oxy-acetylene,  the  gas  pressures  are  approximately  the  same 


FIG.  32.— The  Imperial  Type  B  Welding  Torch. 

as  for  other  makes  of  torches.  For  oxy-hydrogen,  the  pressures 
used  for  various  thicknesses  of  metal  and  different  tips  are  given 
in  Table  V.  However,  neither  the  size  of  the  nozzle  holes  nor 
the  amount  of  gas  used  per  hour  are  given.  This  firm  also 
makes  a  three-way  torch  which  in  outward  appearance  does 
not  differ  from  the  one  shown.  It  is  intended  to  use  a  com- 
bination of  acetylene,  oxygen  and  hydrogen.  The  method  used 

TABLE  V. — PRESSURE  OF  GAS  USED  IN  IMPERIAL  OXY-HYDROGEN 
WELDING  TORCHES 


Thickness  of  Metal 

Pressure,  Lb. 

Welding  Tip  No. 

to  be  Welded,  In. 

Oxygen 

Hydrogen 

1H 

1/64  to  1/32 

10 

10 

2H 

1/32  to  1/16 

12 

12 

3H 

1/16  to  1/4 

15 

15 

4H 

1/4     to  1/2 

20 

20 

5H 

1/2  in.  and  up 

25 

25 

is  to  couple  the  acetylene  and  hydrogen  hose  by  means  of  a 
Y  mixing  valve  from  which  the  two  gases  are  conducted  by  a 
single  hose  to  the  torch,  the  oxygen  hose  being  coupled  in  the 
usual  way.  This  concern  does  not  recommend  the  welding  of 
steel  above  J  in.,  or  cast  iron  above  J  in.  in  thickness  with 
oxy-hydrogen.  For  light  sheet  steel,  and  especially  aluminum, 
oxy-hydrogen  has  some  advantages,  provided  the  hydrogen  can 
be  obtained  at  reasonable  rates.  The  combination  of  oxygen- 


GAS  TORCHES  USED   FOR  WELDING  63 

acetylene-hydrogen,  however,  has  a  claimed  temperature  of 
about  5000  deg.  F.,  which  is  about  half-way  between  that  of 
oxy-hydrogen  and  oxy-acetylene.  It  is  also  claimed  that  this 
flame  possesses  all  the  advantages  of  both  the  double  combina- 
tions. The  same  tips  are  used  as  for  oxy-acetylene,  and  only 
a  small  percentage  of  acetylene  is  needed  to  give  a  cone-shaped 
flame  of  far  greater  visibility  than  that  of  the  oxy-hydrogen 
flame.  The  low  visibility  and  long  flame  of  the  oxy-hydrogen 
flame  are  always  a  handicap  in  welding  to  any  operator  used 
to  employing  the  oxy-acetylene  torch.  The  approximate  pres- 
sures employed  when  using  the  Imperial  three-way  outfit  are 
shown  in  Table  VI. 

TABLE  VI. — PRESSURES  OF  GAS  USED  IN  IMPERIAL  THREE-WAY 

WELDING  TORCHES 
OXYGEN,  ACETYLENE  AND  HYDROGEN 


Oxygen, 
Welding  Tip, 

Thickness  of  Metal, 

Pressures,  Lb. 

No. 

to  be  Welded,  In. 

Oxygen. 

Acetylene, 

Hydrogen. 

IT 

1/32 

3 

2 

- 

2T 

1/16 

5 

3 

3 

3T 

3/32 

6 

4 

4 

4T 

1/8 

7 

5 

5 

5T 

1/4 

8 

6 

6 

6T 

3/8 

9 

7 

7 

7T 

1/2 

10 

10 

10 

8T 

5/8 

12 

12 

12 

9T 

3/4 

14 

14 

14 

10T 

1  in.  and  over 

18 

15 

15 

Calculating  Amount  of  Gas. — It  should  always  be  borne  in 
mind,  when  consulting  a  table  where  only  pressures  are  given, 
that  these  pressures  do  not  signify  the  amount  of  gas  used,  and 
that  such  pressures  apply  only  to  the  particular  make  of  torch 
mentioned.  It  might  be  possible  for  two  different  torches  to 
use  gases  at  exactly  the  same  pressures  as  far  as  the  gages 
indicated,  and  yet  have  one  of  these  torches  use  several  times 
the  amount  of  gases  used  by  the  other.  In  order  to  make  it 
possible  for  a  user  to  estimate  the  amount  of  either  oxygen  or 
acetylene  his  outfit  is  consuming,  three  methods  of  estimating 
are  given  here.  These  methods  are  taken  from  the  Prest-0-Lite 
instruction  book.  Other  methods  have  previously  been  given 


64  GAS  TORCH  AND  THERMIT  WELDING 

in  the  descriptions  of  the  different  gases  and  their  production. 
The  Prest-0-Lite  methods  are : 

Method  1. — Weigh  your  acetylene  cylinders  before  starting  work. 
Weigh  again  after  the  job  is  completed.  Note  the  difference  in  weight 
in  ounces,  and  multiply  by  0.9;  result  equals  the  cu.ft.  of  acetylene 
used.  When  ULing  Prest-O-Lite  torches  multiply  the  acetylene  used 
in  cu.ft.  by  1.1 ;  the  result  equals  the  cu.ft.  of  oxygen  used. 

Method  2. — Take  readings  of  oxygen  cylinder  pressure  gage  in 
atmospheres  before  and  after. 

For  100-cu.ft.  cylinders  the  difference  of  readings  in  atmospheres 
multiplied  by  0.83  equals  the  oxygen  consumption  in  cu.ft. 

For  200-cu.ft.  cylinders  the  difference  in  readings  in  atmospheres 
multiplied  by  1.67  equals  the  consumption  of  oxygen  in  cu.ft. 

For  250-cu.ft.  cylinders  the  difference  in  readings  in  atmospheres 
multiplied  by  2.08  equals  the  consumption  of  oxygen  in  cu.ft. 

When  using  Prest-O-Lite  torches,  multiply  the  oxygen  used  in  cu.ft. 
by  0.91 ;  the  result  equals  the  acetylene  consumption  in  cu.ft. 

Method  3. — Measure  drill  size  of  orifice  in  torch  tip,  using  standard 
drills  for  measuring. 

Area  of  orifice  in  sq.in.  multiplied  by  83  equals  the  acetylene  con- 
sumption in  cu.ft.  per  minute. 

Area  of  orifice  in  sq.in.  multiplied  by  91  equals  the  oxygen  con- 
sumption in  cu.ft.  per  minute. 

Note  the  minutes  the  torch  is  in  use  and  use  the  above  figures  to 
estimate  gas  consumption. 

Remember,  the  acetylene  consumption  cannot  be  accurately  esti- 
mated from  the  pressure  gage  readings. 

In  order  to  simplify  the  calculations  in  Method  3,  the  areas 
of  the  various  orifices  made  with  numbered  drills  are  given  in 
Table  VII.  This  table  was  calculated  by  K.  H.  Condit,  man- 
aging editor  of  the  American  Machinist,  for  both  square  inches 
and  square  millimeters. 

The  Rego  Welding  Torch.— -The  Re  go  welding  torch  is 
made  by  the  Bastian-Blessing  Co.,  Chicago.  The  claim  is  made 
for  this  torch  that  it  will  not  flashback  under  any  condition — 
even  if  the  tip  is  immersed  in  the  molten  metal,  or  if  the  head 
and  tip  are  heated  to  a  cherry  red.  The  elimination  of  the 
flashback  is  accomplished,  not  by  check  valves  but  by  balancing 
the  pressure  of  the  gases  used.  The  tips  used  are  of  one-piece 
nickel-copper  composition.  This  gives  a  harder  tip  than  copper 
alone.  The  gases  are  mixed  in  the  tip  as  shown  in  the  illustration 
Fig.  33.  By  means  of  an  expansion  chamber  within  the  tip 
itself,  the  gases  are  reduced  in  velocity  as  they  come  from  the 


GAS   TORCHES   USED   FOR  WELDING 


65 


TABLE  VII. — AREAS  OF  DRILLS  FROM  1  TO  80  SIZE  IN  SQ.IN.  AND  SQ.MM. 
MANUFACTURERS  STANDARD 


Size  of 

Size  of 

Drill 

Area  in 

Area  in 

Drill 

Area  in 

Area  in 

No. 

in  In. 

Sq.In. 

Sq.Mm. 

No. 

in  In. 

Sq.In. 

Sq.Mm. 

1 

0.2280 

0.04083 

26.35 

41 

0.0960 

0.007238 

4.670 

o 

0.2210 

0.03836 

24.77 

42 

0.0935 

0.006860 

4.426 

3 

0.2130 

0.03563 

22.99 

43 

0.0890 

0.006221 

4.014 

4 

0.2090 

0.03431 

22.14 

44 

0.0860 

0.005809 

3.748 

5 

0.2055 

0.03316 

21.39 

45 

0.0820 

0.005281 

3.406 

6 

0.2040 

0.03269 

21.09 

46 

0.0810 

0.005153 

3.325 

7 

0.2010 

0.03173 

20.47 

47 

0.0785 

0.004831 

3.117 

8 

0.1990 

0.03110 

20.06 

48 

0.0760 

0.004536 

2.926 

9 

0.1960 

0.03017 

19.46 

49 

0.0730  . 

-  0.004185 

2.700 

10 

0.1935 

0.02940 

18.97 

50 

0.0700 

,  0.003848 

2.483 

11 

0.1910 

0.02865 

18.48 

51 

0.0670 

0.003526 

2.275 

12 

0.1890 

0.02806 

18.10 

52 

0.0635 

0.003167 

2.043 

13 

0.1850 

0.02688 

17.34 

53 

0.0595 

0.002781 

1.795 

14 

0.1820 

0.02602 

16.79 

54 

0.0550 

0.002376 

1.533 

15 

0.1800 

0.02545 

16.42 

55 

0.0520 

0.002124 

1.370 

16 

0.1770 

0.02461 

15.88 

56 

0.0465 

0.001693 

1.092 

17 

0.1730 

0.02351 

15.17 

57 

0.0430 

0.001452 

0.9368 

18 

0.1695 

0.02256 

14.56 

58 

0.0420 

0.001385 

0.8930 

19 

0.1660 

0.02164 

13.96 

59 

0.0410 

0.001320 

0.8510 

20 

0.1610 

0.02036 

13.14 

60 

0.0400 

0.001257 

0.8115 

21 

0.1590 

0.01986 

12.81 

61 

0.0390 

0.001195 

0.7710 

22 

0.1570 

0.01936 

12.49 

62 

0.0380 

0.001134 

0.7316 

23 

0.1540 

0.01863 

12.02 

63 

0.0370 

0.001075 

0.6936 

24 

0.1520 

0.01815 

11.71 

64 

0.0360 

0.001018 

0.6568 

25 

0.1495 

0.01755 

11.32 

65 

0.0350 

0.000962 

0.6207 

26 

0.1470 

0.01697 

10.95 

66 

0.0330 

0.000855 

0.5516  - 

27 

0.1440 

0.01629 

10.51 

67 

0.0320 

0.000804 

0.5187 

28 

0.1405 

0.01550 

10.00 

68 

0.0310 

0.000754 

0.4865 

29 

0.1360 

0.01453. 

9.374 

69 

0.0292 

0.000669 

0.4316 

30 

0.1285 

0,01296 

8.361 

70 

0.0280' 

0.000615 

0.3968 

31 

0.1200 

;  0.01131 

7.297 

71 

0.0260 

0.000531 

0.3426 

32 

0.1160 

0.01057 

6.819 

72 

0.0250 

0.000491 

0.3168 

33 

0.1130 

0.01003 

6.471 

73 

0.0240 

0.000452 

0.2916 

34 

0.1110 

0.009677 

6.243 

74 

0.0225 

0.000398 

0.2565 

35 

0.1100 

0.009503 

6.131 

75 

0.0210 

0.000346 

0.2232 

36 

0.1065 

0.008908 

5.747 

76 

0.0200 

0.000314 

0.2020 

37 

0.1040 

0.008495 

5.481 

77 

0.0180 

0.000254 

0.1639 

38 

0.1015 

0.008092 

5.221 

78 

0.0160 

0.000201 

0.1297 

39 

0.0995 

0.007775 

5.016 

79 

0.0145 

0.000164 

0.1058 

40 

0.0980 

0.007543 

4.866 

80 

0.0135 

0.000143 

0.09226 

mixing  chamber,  and  just  before  they  issue  from  the  end  of 
the  tip.  This  produces  a  "soft"  flame  which  melts  the  metal 
without  blowing  it  away. 


66  GAS  TORCH  AND  THERMIT  WELDING 

The  Oxweld  Low-Pressure  Torch. — The  Oxweld  low-pres- 
sure torch  is  of  the  true  injector  type.  One  of  this  make  of 
torch  is  shown  in  Fig.  34  and  in  detail  in  Fig.  35.  In  this 
torch  the  acetylene  is  drawn  into  the  combining  tube  by  the 
injector  action  of  the  high-pressure  oxygen  jet,  in  the  proper 
quantity  to  form  what  is  known  as  a  neutral  flame ;  that  is,  one 


FIG.  33. — The  Rego  Welding  Torch. 

not  having  an  excess  of  oxygen  or  acetylene.  A  torch  of  this 
type  may  be  used  with  either  a  low-  or  positive-pressure  acety- 
lene system,  although  primarily  designed  for  low-pressure 
acetylene,  which  means  at  a  pressure  of  1  Ib.  or  less.  Ten 
hard-drawn  copper  tips,  shown  in  Fig.  36,  are  regularly  sup- 
plied for  this  torch,  and  bodies  may  be  had  to  hold  the  tips 


FIG.  34. — The  Oxweld  Low-Pressure  Welding  Torch. 

at  67  J  or  90  deg.,  although  the  regular  angle  is  45  deg.  The 
tips  shown  are  numbered  2,  3,  4,  5,  6,  7,  8,  10,  12  and  15  and 
are  intended  for  use  on  metal  ^,  ^,  JL-,  £,  ^,  J,  f ,  ±,  f  and 
J  in.  thick  and  up,  respectively. 

A  very  light  torch,  weighing  9  oz.  and  known  as  model  G,  is 
shown  in  Fig.  37.  This  is  intended  for  very  light  sheet  metal, 
instruments,  jewelry  and  the  like.  In  order  to  secure  a  torch 
of  minimum  weight,  the  oxygen  and  acetylene  regulating  valves 


GAS  TORCHES   USED   FOR  WELDING 


67 


have  been  removed  from  the  body  of  the  torch  and  incorporated 
in  a  separate  valve  block  which  may  be  fastened  in  any  con- 
venient position  near  the  operator. 

Another  very  light  torch  is  shown  in  Fig.  38.     This  is  suit- 


Oxygen 

Oxygen 

Hose- 

Connection 


Acetylene 
Hose  Conn. 


Oxygen  Chamber 
%       ,'lnjec+or 

"Acetylene 
Chamber 

'Mixing 
Chamber 


^Acetylene 
Va/ve 

FIG.  35. — Details  of  the  Oxweld  Welding  Torch. 


able  for  metals  up  to  -J  in.  thick.  In  addition  to  the  usual 
practice  of  placing  needle  valves  in  the  rear  body,  there  is  also 
incorporated  in  the  torch  head  a  needle  valve  which  gives  minute 
control  of  the  flame  with  each  size  of  tip.  Three  sizes  of  in- 


3     4      5      6      7      8      1O      12  '  15 


FIG.  36. — A  Set  of  Oxweld  Welding  Tips. 

terchangeable  copper  tips  are  supplied.     It  is  10  in.  long  and 
weighs  10  oz. 

The    Oxweld    water-cooled    machine    torches    are    shown    in 
Figs.  39  and  40.     Fig.  39  is  a  single-jet,  known  as  type  W-8, 


68 


GAS   TORCH  AND   THERMIT   WELDING 


§ 
a 

I 


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*-c 

£ 


s  - 

J* 


GO 


a 


:oo 


d 
Q,J 


ddpddodd^w 


*H  C<1  CO  CO  O5  COt>«  rH  O  C<l  t^ 

ddddd^<Nco^iioo! 


CO  CQ  W  CO  W  C^  CO.  CO  CO  "^  CO 

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60066 


GAS  TORCHES  USED   FOR  WELDING 


69 


and  is  adapted  to  work  on  cartridge  cases,  pistol  magazines,  or 
any  light  sheet-metal  work  that  can  be  fed  mechanically.     Fig. 


FIG.  37. — The  Oxweld  Welding  Torch  Model  G. 


FIG.    38.— The    Oxweld    Sheet-Metal    Welding    Torch 


FIG.  39.— The  Oxweld  Water-Cooled  Single-Jet  Welding  Torch,  Type  W-8. 

40  is  known  as  type  W-5,  and  is  a  multiple-jet  torch  suitable 
for  v/elding  metal  up  to  3/32  in.  thick,  and  is  designed  for  con- 


70 


GAS  TORCH  AND  THERMIT  WELDING 


tinuous  operations  on  tube  stock  or  other  mechanically  handled 
work. 

In  Table  VIII,  which  is  taken  from  the  Oxweld  handbook, 
the  various  thicknesses  of  metal,  the  oxygen  pressure,  hourly 


FIG.  40. — The  Oxweld  Water-Cooled  Multiple-Jet  Welding  Torch,  Type  W-5. 

gas  consumption,  consumption  per  foot  and  amount  of  wire 
used,  are  shown.  In  this  table  the  acetylene  is  used  at  1-lb. 
pressure. 

The  Messer  Torch. — The  torch  shown  in  Fig.  41  and  in 


FIG.  41. — The  Messer  Welding  Torch  and  Tips. 

detail  in  Fig.  42  is  made  by  the  Messer  Manufacturing  Co., 
Philadelphia,  Penn.  It  works  on  the  injector  principle  and 
may  be  used  with  either  low-  or  positive-pressure  acety- 
lene systems.  This  make  is  notable  on  account  of  the  single 
valve  in  the  torch  itself,  and  the  tips,  which  are  bent,  may  be 


GAS  TORCHES   USED   FOR   WELDING  71 

set  at  any  angle  radial  with  the  torch  body.  The  various  sizes, 
tips  and  general  range  arc  practically  the  same  as  for  the  torches 
previously  described. 

The  Oxy-Thermalene  Welding  Torch. — An  oxy-thermalene 
welding  torch  and  a  set  of  tips,  are  shown  in  Fig.  43.  Details  of 
the  head  are  shown  in  Fig.  44.  One  of  these  torches  is  about 
17  in.  long  and  weighs  24  oz.  Referring  to  the  detailed  cut,  the 


FIG.  42. — Details  of  the  Messer  Welding  Torch. 

oxygen  enters  at  A  and  the  thermalene  at  B.  The  oxygen 
nozzle  is  at  C.  Screens  are  placed  at  D.  One  of  the  troubles 
with  some  torches  is  the  fact  that  frequently  a  flashback  will 
occur,  reaching  the  oxygen  nozzle  in  the  gas  chamber.  Here  a 
flame  would  be  formed  which  would  burn  out  the  entire  copper 
tip.  In  the  torch  shown  it  is  claimed  this  does  not  occur.  It 
will  be  seen  that  the  gas  chamber  is  comparatively  large,  while 


FIG.  43. — A  Thermalene  Welding  Torch  and  Tips. 

the  orifice  leading  from  the  gas  chamber  to  the  mixing  chamber 
is  restricted  and  elongated.  This  orifice  is  enlarged  abruptly 
to  the  mixing  chamber  in  the  nozzle,  so  as  to  form  sharp 
corners  at  E.  The  mixing  chamber  gradually  contracts  to  the 
outer  opening  in  the  nozzle.  As  a  result,  if  a  flashback  should 
occur,  it  will  cause  a  whirl  or  eddy  at  the  shoulder  E,  which 
in  itself  will  prevent  the  flame  from  running  back  through  the 
restricted  channel.  Moreover,  such  propagation  of  the  flame 
into  the  mixing  chamber  will  cause  the  gas  in  the  chamber  to 


72 


GAS  TORCH  AND   THERMIT  WELDING 


be  pressed  back  by  the  increased  expansion  and  pressure, 
so  that  there  will  be  only  burnt  gas  in  the  restricted  channel 
and  around  the  oxygen  tip.  The  result  is  that  the  flame  will 


FIG.  44. — Details  of  the  Thermalene  Welding  Torch  Head. 

die  out  in  the  restricted  channel  between  the  gas  and  mixing 
chambers,  so  that  a  cutting  flame  is  never  formed  at  the  oxygen 
nozzle.  It  is  necessary,  however,  that  these  parts  should  be 
properly  proportioned  to  obtain  the  desired  results. 

TABLE  IX. — AMOUNT  OF  OXYGEN  AND  THERMALENE  USED  FOR  WELDING 


Thick- 
ness of 
Metal 

Consump- 
tion of 
Thermalene, 

Consumption 
of  Oxygen 
with  Therma- 

Oxygen 
Pressure, 
with  Therma- 

Tip No. 

in  Inches 

Ft. 

lene,  Ft. 

lene,  Lb. 

1      

A  to  A 

2.15 

2.55 

1.0 

2            , 

,         A  to  ?s 

3  32 

3  99 

2ito3 

3  , 

&  to  | 

5.51 

6.52 

3    to3i 

4               

8.29 
11.78 
16  48 

10.11 
14.21 
20  10 

3}  to  4  J 
5   to  5} 

6J  to  1\ 

5  , 

6              

7  , 

A  to  1 

21  40 

27  51 

10   to  11 

8 

f  to  1 

25  00 

35  01 

11    to  12 

9.. 

i  to  I 

33  60 

54  21 

15 

10 

i  to  ij 

48  05 

75  30 

20  to  22 

11... 

li  to  11 

70  35 

101  62 

25  to  28 

12 

l|to2 

91.10. 

159.20 

25  to  30 

For  various  welding  purposes,  12  sizes  of  tips  are  made  to 
be  screwed  into  the  torch  bodies.  These  tips  run  from  2  to  4 
in.  in  length,  and  the  outlets  vary  from  the  size  of  a  No.  80 


GAS  TORCHES  USED   FOR  WELDING  73 

to  No.   33   drill.     All  have   Vie-in  wrench-holds   on  them  for 
screwing  into  the  torch  bodies. 

Table  IX  will  furnish  a  good  idea  of  the  amount  of  therma- 
lene  and  oxygen  used  per  hour  for  different  thicknesses  of 
metal,  the  torch  being  fitted  with  the  proper  nozzle  in  each  case. 


CHAPTER  VI 
GAS  CUTTING-TORCHES 

The  gas  cutting-torch  is  commonly  used  for  cutting  through 
various  thicknesses  of  steel  or  wrought  iron,  which  are  the  only 
metals  which  can  be  satisfactorily  or  economically  cut  by  this 
process.  Cast  iron  cannot  be  satisfactorily  cut  with  a  gas  torch. 
As  an  adjunct  to  a  welding  outfit,  the  cutting-torch  is  used  for 
beveling  and  for  cutting  out  patches  and  holes.  The  process  is 
based  on  the  fact  that  a  jet  of  oxygen  directed  upon  a  previously 
heated  spot  of  iron  or  steel,  causes  it  to  ignite  with  the  result 
that  the  metal,  acting  as  its  own  fuel,  burns  away  rapidly  in 
the  form  of  iron  oxide.  This  oxide  runs,  or  is  blown,  out  of 
the  cut  or  kerf  produced,  in  a  stream,  provided  the  torch  is 
fed  along  properly.  The  same  sources  of  gas  supply  may  be 
used  as  for  welding,  though  in  some  cases  other  regulators  must 
be  employed. 

As  previously  stated,  steel  and  wrought  iron  are  the  only 
metals  which  can  be  satisfactorily  cut  by  this  process.  The 
reason  is  that  these  two  metals  combine  readily  with  oxygen, 
with  the  liberation  of  heat.  The  slag  is  produced  at  a  tempera- 
ture below  that  of  the  melting  point  of  the  metal,  with  the  result 
that  it  is  easily  separated  from  it.  Other  metals  do  not  produce 
so  much  heat  when  combining  with  oxygen,  and  the  oxide  formed 
is  not  reduced  to  a  molten  condition  at  temperatures  below  that 
of  the  melting  point  of  the  metal,  with  the  result  that  it  cannot 
be  easily  separated. 

The  combination  of  the  oxygen  with  the  iron  is  not  that  of 
complete  combustion.  An  examination  of  the  slag  produced 
shows  the  presence  of  metallic  iron,  which  leads  to  the  belief 
that  the  oxidation  follows  the  grain  surfaces  of  the  metal  and 
more  or  less  mechanically  disintegrates  the  mass  at  the  line  of 
cutting. 

Cutting  torches  use  a  single  high-pressure  oxygen  jet  for  the 

74 


GAS  CUTTING-TORCHES 


75 


cutting.    This  jet  has  one  or  .more  heating  jets  in  line  with,  or 
surrounding  it. 

Since  the  temperature  to  which  it  is  necessary  to  heat  the 
iron  or  steel,  in  order  to  have  the  oxygen  act,  is  comparatively 
low  (about  900  deg.  F.)  a  number  of  gases  may  be  used  for 
heating.  Oxy-acetylene  is  very  commonly  used  on  account  of 
its  convenience,  for  ordinary  work.  For  heavy  work  oxy- 
hydrogen  is  used  on  account  of  its  longer  flame  and  because 
no  products  of  combustion  that  hinder  cutting;  are  produced. 
The  temperature  required  is  well  within  its  heafing  range, 
and  steel  up  to  36  in.  thick  has  been  cut.  The  thicker  the 
metal  the  greater  the  pressure  of  oxygen  used,  as  will  be  seen 


/CUTTING    OXYGEN 


PREHEATING  OXYGEN  VALVE 


REMOVABLE  PLUG 


,,   1,1  1 

.  I'IIM', 


CUTTING  VALVE 
TRIGGER 

r/fema/ns  in  open  Posifion) 


PACKING 
NUT 


''SPRING 


FIG.  45. — Details  of  the  Davis-Bournonville  Cutting  Torch. 

from  the  various  tables.  In  the  cutting  torches,  the  holes  for 
the  various  jets  are  usually  drilled  in  the  same  tip,  though  in 
some  cases  separate  tips,  set  close  together,  are  used.  The 
ordinary  cut  or  kerf  made  by  the  cutting  torch  is  from  1/ltt 
to  \  in.  wide,  according  to  the  size  of  the  oxygen  jet  used. 

Since  the  same  construction  of  the  heating  part  of  a  cutting 
torch  is  used  as  in  the  welding  torch,  it  naturally  follows  that 
both  the  positive-pressure  and  low-pressure,  or  injector  types 
of  heating  units  are  used  in  conjunction  with  the  single  oxygen 
cutting  jet. 

The  Davis-Bournonville  Cutting  Torches. — The  details  of 
a  Davis-Bournonville,  No.  3000,  cutting  torch  are  shown  in 
Fig.  45.  This  is  typical  of  the  general  principle  on  which  all 
of  this  firm's  cutting  torches  are  made.  In  use,  the  positive- 


76 


GAS  TORCH  AND  THERMIT  WELDING 


pressure  heating  unit  is  first  started  and  applied  to  the  work 
to  be  cut.  As  soon  as  the  metal  .reaches  a  red  heat,  the  trigger 
is  pressed  and  the  oxygen  jet  commences  its  work.  This  par- 
ticular model  of  torch  is  supplied  with  five  interchangeable 
tips,  and  the  cutting  jet  of  oxygen  may  be  turned  on  or  off 
by  a  simple  pressure  of  the  trigger,  as  just  mentioned.  This 
trigger  is  so  made  that  it  is  not  necessary  to  keep  the  finger 
011  it  all  the  time  it  is  in  use.  There  are  only  two  hose  con- 
nections for  the  gases,  one  for  oxygen  and  one  for  acetylene. 


11  1 

1              G 

Y 


FIG.  46- — Various  Models  of  the  Davis-Bournonville  Cutting  Torches. 

The  pressures  of  the  respective  gases  vary  with  the  thickness 
of  the  metal  being  cut,  which  may  be  from  J  up  to  12  in.  or 
more.  The  torch  is  20  in.  over  all,  and  is  especially  adapted 
to  freehand  cutting,  and  in  wrecking  or  scrapping  metal. 

A  number  of  different  styles  of  cutting  torches  are  shown 
in  Fig.  46.  A  is  a  straight-head  cutting  torch  (No.  2018) 
which  may  be  fitted  with  curved  tips  for  cutting  boiler  tubes, 
rivet  heads,  etc.  Three  bent  and  two  straight  tips  are  regu- 
larly furnished.  '  In  general,  it  closely  resembles  No.  3000. 

The  torch  B,  known  as  No.  1316,  is  very  much  like  the  first 
torch  described,  except  it  is  intended  for  use  with  oxy- 


GAS  CUTTING-TORCHES 


77 


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I 


1 

kvo 


£^ 


(S) 

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£»g 

si 
££ 


78 


GAS  TORCH  AND  THERMIT  WELDING 


hydrogen.  Torcli  C  (No.  471)  is  a  circle  cutting  torch  fitted 
with  a  15-in.  radius  rod  adjustable  for  various  sizes  of  circles. 
It  uses  either  oxy-acetylenc  or  oxy-hydrogen  for  heating,  and 
takes  all  standard  size  tips.  It  is  the  standard  torch  for  nick- 
ing billets  for  breaking.  It  may  be  had  fitted  with  special 
adjustable  holder,  rack  and  pinion,  for  machine  cutting. 

TABLE  X. — GAS  PRESSURES  USED  WITH  THE  DAVIS-BOURNONVILLE  STYLE 
C    CUTTING   TORCHES,    USING    STYLE    12    TIPS 


tip 

Thickness 
of  Metal 

Acetylene 
Pressure 

Oxygen 
Pressure 

.        No. 

Inches 

Lbs. 

Lbs. 

1 

H 

3 

10 

1 

3 

15 

1 

% 

3 

20 

1 

% 

3 

20 

2 

1A 

3 

10 

2 

K 

3 

20 

2 

% 

3 

30 

2 

1 

3 

35 

3 

l 

4 

30 

3 

IK 

4 

40 

3 

2 

4 

50 

.3 

3 

4 

60 

4 

3 

5 

60 

4 

4 

5 

70 

4 

5 

5 

85 

4 

6 

5 

100 

5 

6 

6 

90 

5 

7 

6 

10.0 

5 

8 

6 

125 

5 

10 

8 

150 

Torch  D,  No.  640,  is  a  machine  cutting  torch  for  use  with  the 
different  cutting  machines  made  by  the  Davis  company.  It 
is  fitted  with  an  electric  switch  and  shut-off  valve  which  auto- 
matically starts  the  cutting-machine  feed  when  the  oxygen 
cutting  jet  is  turned  on,  without  the  necessity  of  readjusting 
pressures  or  the  heating  flame.  It  uses  all  standard-size  cutting 
tips  and  special  Oxygraph  and  Radiograph  tips.  A  larger  and 


GAS   CUTTING-TORCHES 


79 


heavier  torch  of  similar  design  and  construction  for  oxy- 
hydrogen  machine  work  is  shown  at  E.  This  is  known  as 
No.  1314.  Larger  sizes,  or  special  torches  used  for  cutting, 
are  water-cooled.  Tips  of  various  styles,  for  different  pur- 
poses, which  may  be  used  with  the  torches  mentioned,  are 
shown  in  Fig.  47. 

The  approximate  oxygen  and  acetylene  pressures  used  in 


FIG.  48.— The  Oxweld  Cutting  Torch,  Model  B. 

the  Davis  style  C  cutting  torches,  using  style  No.  12  tips,  are 
given  in  Table  X.  As  in  welding,  these  pressures  are  only 
general  guides  for  the  make  of  torch  mentioned,  and  the 
skilled  operator  usually  adjusts  his  flame  regardless  of  the 


Cuftmq  Oxyqen 
.-Valve   Lever 


FIG.  49.— Details  of  the  Oxweld  Cutting  Torch,  Model  B. 

tables  given,  since  a  neutral  heating  flame  is  essential  at  all 
times  for  satisfactory  results. 

Oxweld  Cutting  Torches. — An  Oxweld  low-pressure  or  in- 
jector type  of  cutting  torch  is  shown  in  Pig.  48.  This  is  their 
model  B.  Details  are  shown  in  Fig.  49.  In  this  torch,  the 
cutting  jet  is  entirely  surrounded  by  the  preheating  flame,  as 
the  oxy-acetylene  is  delivered  through  six  openings  arranged 


80  GAS   TORCH  AND   THERMIT  WELDING 

in  a  circle  around  the  orifice  for  the  oxygen  jet.  This  arrange- 
ment makes  it  possible  for  the  preheating  flarne  to  always 
precede  the  cutting  jet,  no  matter  in  what  position  the  torch 
is  held,  or  in  whatever  direction  the  cut  is  made,  be  it  hori- 
zontal, transverse,  circular,  elliptical,  toward  or  away  from 
the  operator.  In  so  working,  the  operator  does  not  have  to 
shift  his  postion  or  turn  the  torch.  This  is  especially  valuable 
in  wrecking  steel  structures,  removing  risers  from  steel  cast- 
ings, or  cutting  steel  scrap,  especially  where  places  difficult 
of  access  are  encountered.  The  preheating  flame  is  produced 
in  practically  the  same  way  as  in  the  welding  torch  previously 
shown. 

There  is  a  separate  valve  for  controlling  the  oxygen  to  the 
preheater,  which  enables  the  operator  to  secure  close  adjust- 
ment and  avoid  waste  of  gas.  The  oxygen-jet  valve  is  of  the 


FIG.   50. — The   Oxweld   Cutting   Torch   with   a   Rivet-Head   Cutting-Nozzle. 

plunger  type,  which  is  so  constructed  that  its  movement  pro- 
duces no  tendency  to  deflect  the  cutting  jet  from  the  line  of 
the  cut.  The  location  of  the  valve  lever  is  on  top  of  the 
handle  and  its  motion  is  in  the  direction  of  the  vertical  center 
plane  of  the  torch.  The  valve  is  held  open  for  continuous 
cutting,  when  desired,  by  a  simple  but  effective  button-like 
latch,  which  may  be  instantly  engaged  or  released  by  a  slight 
movement  of  the  thumb.  The  external  nozzle  is  furnished 
with  a  copper  tip.  The  internal  nozzle  is  held  in  place  by 
tightening  the  external  nozzle.  To  remove  the  former  it  is 
only  necessary  to  unscrew  the  external  nozzle.  This  torch  is 
regularly  furnished  with  four  interchangeable  tips,  for  cutting 
up  to  1  in. ;  from  1  to  3  in. ;  from  3  to  6  in. ;  and  from  6  in.  up. 
A  model-B  torch  fitted  with  a  special  rivet-head  cutting 
nozzle  is  shown  in  Fig.  50.  Another  form,  known  as  model 


GAS   CUTTING-TORCHES 


81 


FIG.  51.— The  Oxweld  Cutting  Torch  for  Ship  Work. 


FIG.   52. — The   Oxweld   Staybolt   Cutting-Torch. 


82  GAS  TORCH  AND  THERMIT  WELDING 

C-6,  is  shown  in  Fig.  51.  This  was  made  to  meet  the  demand 
for  a  light,  rugged  and  adaptable  cutting  torch  for  work  on 
double  bottom's  and  below  decks  of  ships.  In  general,  it  closely 
resembles  the  other  models.  It  weighs  2J  Ib.  and  is  20  in. 
overall. 

For  cutting  inner  and  outer  shells  of  locomotive  fireboxes, 
where  length  and  slenderness  is  necessary,  the  staybolt  cutting 
torch  shown  in  Fig.  52  has  been  made.  This  is,  however, 
merely  a  special  form  of  the  model  B.  The  long  "stem"  is 
made  up  of  three  gas  tubes  as  shown.  This  torch  is  regularly 
furnished  in  42,  54,  69  and  84  in.  lengths  to  suit  the  needs  of 
the  user.  The  84-in.  torch  weighs  6J  Ib.  The  head  is  set  at 
an  angle  of  20  deg.,  which  experience  has  shown  is  the  more 
generally  useful.  All  the  regular  nozzles  can  be  used  with 
this  torch. 

In  addition  to  the  torches  mentioned,  the  Oxweld  Acetylene 
Co.  makes  straight-tipped  machine  cutting  torches,  which  may 
be  used  on  any  of  the  cutting  machines  on  the  market.  Like 
all  other  cutting  torches,  small  guide  wheels  may  be  used  for 
steadying  the  torch  when  cutting  to  straight,  irregular  or 
circular  lines  by  hand. 

In  Table  XI  are  given  the  oxygen  pressures  and  amount  of 
gas  consumption  for  various  thicknesses  of  metal.  The  acety- 
lene pressure  is  the  same  as  for  welding,  1  Ib.  With  the  data 
given  in  this  table,  and  knowing  the  cost  of  acetylene  and 
oxygen,  the  approximate  cost  of  gas  for  any  given  job  may 
be  calculated  with  a  fair  amount  of  accuracy  and  serve  as  a 
basis  for  price  estimates.  It  must  be  kept  in  mind  that  old 
rusty  metal,  like  boiler  plate,  will  take  much  more  gas  than 
will  clean  metal. 

Other  Cutting  Torches. — In  order  to  give  the  reader  an 
idea  of  the  construction  of  some  of  the  other  well-known  cut- 
ting torches,  a  few  will  be  shown.  Fig.  53  shows  details  of 
a  cutting  torch  made  by  the  Messer  Manufacturing.  Co.,  Phila- 
delphia. This  type  of  torch  will  use  either  medium  or  low- 
pressure  acetylene,  as  it  works  on  the  injector  principle  which 
is  independent  of  the  acetylene  pressure.  The  oxygen  jet  is 
operated  by  means  of  the  lever  shown  on  top.  The  wheel 
guides  are  adjustable  so  that  the  tip  may  be  kept  the  proper 
distance  from  the  work. 


GAS  CUTTING-TORCHES 


83 


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84  GAS  TORCH  AND  THERMIT  WELDING 

The  construction  of  the  cutting  torch  made  by  the  General 
Welding  and  Equipment  Co.,  Boston,  Mass.,  is  shown  in  Fig. 
54.  The  valve  lever  for  the  cutting  jet  has  a  lock  that  is 
easily  manipulated  with  the  thumb.  This  torch  will  use  either 
medium-  or  low-pressure  acetylene,  and  like  the  other  torches, 
will  use  either  acetylene  or  hydrogen  with  the  oxygen.  The 


FIG.  53. — Details  of  the  Messer  Cutting  Tools. 


FIG.  54. — Details  of  the  Cutting  Torch  Made  by  the  General  Welding  and 

Equipment  Co. 

parts  are  easily  changed  when  necessary.  The  head  is  fastened 
to  the  mixing  chamber  by  means  of  a  ground-joint  swivel  and 
loose-nut  coupling.  The  swivel  is  brazed  into  the  head  so 
as  to  make  a  tight  joint  even  under  heat.  The  mixing  chamber 
can  be  easily  taken  out  and  cleaned.  The  lever  key  is  accessible 
from  all  sides  and  the  seat  can  be  replaced  in  a  few  minutes. 
As  has  been  previously  mentioned,  the  consumption  of  the 


GAS   CUTTING-TORCHES 


85 


various  gases  for  different  work  can  be  only  approximately 
estimated  beforehand,  as  so  many  elements  enter  into  the 
work.  Even  in  cutting  the  same  piece,  if  the  cut  is  of  any 
length,  the  gas  consumption  and  time  will  often  vary  to  a 
marked  extent  from  different  causes.  Parts  may  be  clean  and 
others  rusty.  The  operator's  skill  will  vary  as  he  is  fresh  or 
tired,  and  many  other  reasons  may  enter  into  the  calculations. 
However,  tabulations  of  specific  results  may  often  be  of  con- 
siderable value.  Those  already  given  have  been  for  average 
conditions,  and  are  believed  to  be  as  near  correct  as  it  is  pos- 
sible to  get  them.  The  company  making  the  torch  last  men- 
tioned has  made  some  calculations  regarding  the  time  taken 
to  cut  clean  metal,  which  will  be  of  interest.  On  J-in.  steel, 
the  time  for  cutting  1  ft.  with  a  regular  machine  cutting  tip, 
was  0.67  min.  and  by  hand,  0.90  min. ;  for  1-in.  steel,  1.25  and 
1.50  min.  respectively;  for  2  yi.,  1.40  and  1.60  min.;  for  4  in., 
1.50  and  2.00  min. ;  for  6  in.,  3.00  and  4.00  min.  and  for  8  in., 
3.25  and  4.50  min. 

An  8-in.  steel  shaft  was  cut  through  in  3  min.,  using  14 
cu.ft.  of  oxygen ;  an  18-in.  shaft  was  cut  in  16  min.  with  250 
cu.ft.  of  oxygen ;  a  20-in.  shaft  in  18  min.  and  300  cu.ft.  of 
oxygen.  For  the  last  two  oxy-hydrogen  was  used. 

The  cutting  of  steel  risers  and  shafts,  under  what  is  claimed 
to  be  average  conditions,  is  tabulated  as  shown  in  Table  XII. 
The  tests  are  classified  as  follows : 

TABLE  XII. — CUTTING  STEEL  RISERS  WITH  THE  GENERAL  WELDING  AND 
EQUIPMENT  Co.  TORCHES 


i  ; 

o  I 

O 

TEST 

SHAPE  OF  CUT 

§ 

0 

h 

ii 

I    0 

i  t 

2 
Ij 

U 

NO. 

h 

!  a 

II 

i 

II 

ii 

\\ 

11 

i 

1 

Different  shapes,    ) 
1  in.  to  5  in.  thick    ) 

40 

615 

248 

2.84 

— 

- 

2a   1 

Wheel  rim  If  in. 

(     10 

94.5 

8 

11.8 

22.5 

4.17 

2b  ) 

to  2Y2  in.  thick 

i    10 

100.6 

10.4 

9.67 

18.3 

5.5 

3 

6J^  in.  x  8  in. 

52 

14 

3.7 

27.1 

1.92 

4 

5  in.  x  10  in. 

50 

18 

2.78 

20 

1.5 

5 

5>2  in.  x  15  H  in. 

85.25 

34 

2.5 

22.8 

3.75 

6 

5^2  in.  x  15)4  in. 

85.25 

28 

3.04 

26.2 

3.25 

7 

5>2  in.  x  16^  in. 

90.75 

2.84 

27.9 

3.25 

8 

11  in.  x  11  in. 

242 

112 

2.16 

— 

— 

9 

6  in.  diameter 

113 

46 

2.48 

11.3 

10.00 

10 

15  "         '« 

177 

162 

1.1 

12.6 

14.00 

11 

16  "          •• 

200 

200 

1.0 

14.3 

14.00 

12 

18  V-        «• 

254 

250 

1.0 

15.9 

16.00 

13 

20  "          •• 

314 

300 

1.05 

17.3 

18.00 

86  GAS  TORCH  AND   THERMIT  WELDING 

Test  No.  1  comprises  ordinary  work  as  it  came  along.  Risers  were 
not  clean  and  especially  the  smaller  risers  had  sand  and  holes  in  the 
core.  The  oxygen  consumption  contains  all  the  waste  changing  from 
one  piece  to  another. 

Test  No.  2a  was  made  on  clean  metal  with  oxy-acetylene  and  with 
a  special  pointed  tip. 

Test  No.  2b  was  the  same  as  No.  2a  but  cut  with  oxy-hydrogen,  a 
regular  tip  being  used. 

Test  No.  3  was  made  on  a  very  clean  riser.  The  operator  could  rest 
his  hand  very  comfortably.  The  cut  looked  as  if  it  was  done  by 
machine. 

Tests  Nos.  4-7. — Cuts  were  made  on  risers  of  a  20-ft.  flywheel. 
Cleaning  was  only  superficially  done  and  operator  was  in  a  fair,  but 
not  ideal  position.  One  riser  showed  a  large  blow-hole.  The  cuts 
were  clean  through. 

Test  No.  8. — Two  cuts  were  made  on  the  same  flywheel.  Risers 
were  well-cleaned,  but  the  cranes  could  not  be  spared  to  bring  the 
face  of  the  risers  into  a  horizontal  line.  They  had  to  be  cut  diagonally 
and  the  operator  had  to  bend  so  far  over  that  with  the  first  riser  he 
lost  his  balance  and  fell  and  had  to  interrupt  the  operation,  therefore, 
no  time  was  taken.  The  maximum  thickness  of  the  cut  was  13  in. 
The  cuts  were  clean  through. 

Tests  No.  9-13. — Cuts  were  made  on  risers  of  circular  shape.  The 
number  of  sq.in.  cut  per  cu.ft.  of  oxygen  is  in  the  average  lower  than 
with  rectangular  shapes,  as  it  is  too  cumbersome  to  regulate  the 
oxygen  pressure  according  to  the  varying  thickness.  It  does  not  pay 
to  start  with  lower  pressure  at  the  beginning  and  increase  it  the  more 
the  cutter  is  nearing  the  center  or  full  thickness  of  the  metal.  More- 
over, the  cuts  were  made  with  a  two-line  cutting  torch  so  that  the 
preheating  flames  would  have  suffered  with  regulating  the  oxygen 
pressure  in  such  wide  limits.  With  the  heavier  cuts  of  15  in.,  16.  in., 
18  in.  and  20  in.  thickness,  the  principal  consideration  was  to  cut 
through  rather  than  to  get  stuck,  and  not  look  too  close  to  the  oxygen 
consumption. 

The  Imperial  Brass  Manufacturing  Co.,  Chicago,  makes  the 
cutting  torches  shown  in  Fig.  55.  These  are  of  the  positive- 
pressure  type.  A  is  a  combination  cutting  and  welding  torch, 
the  oxygen  pipe  and  tip  being  detachable,  so  that  the  curve 
tip  may  be  put  on  when  the  torch  is  wanted  for  welding.  B 
is  a  cutting  torch  only.  Either  may  be  used  for  oxy-acetylene 
or  for  oxy-hydrogen.  "When  using  oxy-hydrogen,  the  respective 
pressures  are  given  in  Table  XIII. 

The  torches  may  also  be  used  for  the  company's  three-way 
gas  system,  which  uses  a  combination  of  acetylene,  hydrogen, 
and  oxygen,  as  explained  under  welding  torches.  The  acety- 


GAS  CUTTING-TORCHES  87 

TABLE   XIII. — PRESSURES   FOR  OXY-HYDROGEN   CUTTING   WITH    IMPERIAL 

TOUCHES 


Thickness  of  Wrought 

Cutting 

Iron  or  Steel 

P 

!d1T*£kC< 

Tip 

to  be  Cut,  In. 

Oxygen,  Lb. 

Hydrogen,  Lb. 

1H 

4  to     2 

30  to     40 

5  to  10 

2H 

2  to     4 

50  to     70 

10  to  15 

3H 

4  to     6 

80  to  100 

15  to  20 

4H 

6  to     9 

100  to  125 

20  to  25 

5H 

9  to  12 

125  to  150 

25  to  30 

These  figures  represent  minimum  and  maximum  pressures.     For  in- 
termediate  thicknesses  use  pressures  in  proportion.    

lene  and  hydrogen  are  mixed  through  a  Y-valve  and  enter  the 
torch  through  the  same  hose.  Pressures  when  the  gases  are 
used  in  this  way  are  shown  in  Table  XIV. 

TABLE  XIV. — PRESSURES  WHEN  USING  THREE-WAY  GAS  SYSTEM 


Thickness  of 

Steel  or 

Cutting 

Wrought  Iron 

Pressures 

Tip,  No. 

to  be  Cut,  In. 

Oxy 

gen 

,Lb. 

Acetylene,  Lb. 

Hydrogen,  Lb. 

IT 

4  to     2 

30 

to 

40 

5 

5 

to 

10 

2T 

2  to     4 

50 

to 

70 

5 

10 

to 

15 

3T 

4  to     G 

80 

to 

100 

10 

15 

to 

20 

4T 

6  to     9 

100 

to 

125 

10 

20 

to 

25 

5T 

9  to  12 

125 

to 

150 

15 

25 

to 

30 

and  over 

The  Carbo-Hydrogen  Co.,  Pittsburgh,  Penn.,  makes  two 
models  of  the  injector-type  hand  cutting  torches,  shown  in 
Figs.  56  and  57,  and  in  detail  in  Fig.  58.  They  also  make 
straight-nozzle  machine  torches.  Mechanical  guides,  or  wheels, 
may  be  had  for  attaching  to  the  regular  hand  models,  or  to  the 
straight-nozzle  torches.  Tips  are  furnished  in  a  number  of 
interchangeable  sizes  and  shapes.  They  are  made  from  a 
solid  brass  bar,  with  an  outer  shell  of  copper  solidly  attached 
with  rivets.  The  preheating  holes  are  arranged  closely  around 
the  cutting  orifice  so  that  the  flame  cones  do  not  have  a 
tendency  to  melt  edges  of  the  cut.  It  is  claimed  that  the  tips 
remain  cool  and  do  not  have  to  be  dipped  in  water  to  keep 
them  cool  when  used  for  long  periods.  The  regular  sizes  of 
the  tips  are  arranged  for  cutting  from  the  thinnest  metals  up 
to  18  in.  in  thickness,  or  more  with  special  tips.  The  head  and 


88 


GAS  TORCH  AND  THERMIT  WELDING 


base  castings  of  the  torches  are  of  Tobin  bronze  and  the 
tubes  are  of  seamless  drawn  steel,  surrounded  by  an  aluminum 
or  a  fiber  handle.  A  special  swivel-point  valve  stem,  instead 
of  the  usual  solid  needle  point,  is  used  for  controlling  the 


FIG.   55. — The   Imperial   Cutting   Torches 


FIG.  56. — Carbo-Hydrogen  Model  C  Cutting  Torch 


FIG.  57. — Carbo-Hydrogen  Model  B  Cutting  Torch. 

combustion  gas.  All  parts  are  easily  removed  for  cleaning,  and 
the  injector  may  be  taken  out  with  a  pair  of  pliers.  These 
torches  are  designed  for  use  with  oxy-carbo-hydrogen  gas. 
Carbo-hydrogen  is  a  fixed  gas,  permanent  under  all  weather 
conditions.  Since  it  does  not  solidify  there  is  said  to  be  no 
residue  left  in  the  tanks  or  cylinders  at  any  time.  It  is  clean, 


GAS  CUTTING-TORCHES 


89 


easy  to  use,  and  safe,  since  it  is  combustible  but  not  explosive 
within  itself.  It  is  a  product  of  the  destructive  distillation 
of  suitable  hydro-carbons,  and  has  a  general  analysis  of  85 
per  cent  hydrogen  and  15  per  cent  light  hydro-carbons.  It  is 
claimed  that  this  gas  has  no  tendency  to  harden  the  surface 
of  the  metal  being  cut.  It  is  not  a  sensitive  gas,  and  backfiring 
is  rare.  It  is  marketed  in  steel  cylinders  under  1800  Ib.  pres- 


BASE  CASTING 


Section  of 
Base  Casting 
through  High 
Pressure  Valve 


FIG.  58. — Details  of  Carbo-Hydrogen  Cutting  Torches. 

sure  and  of  about  the  usual  capacity.  The  pressure  is  reduced 
to  from  5  to  10  Ib.  for  working  purposes,  5  Ib.  being  the  pressure 
usually  employed. 

In  Table  XV  are  shown  the  approximate  number  of  feet 
cut  per  hour,  the  pressure  of  the  oxygen  and  the  amounts  of 
the  gases  used  per  lineal  foot  of  cut.  The  carbo-hydrogen 
pressure  is  5  Ib.  in  each  case. 

TABLE  XV. — GAS  CONSUMPTION  AND  PRESSURES  WHEN  USING  OXY-CARBO- 
HYDROGEN  CUTTING-TORCHES.  THE  CARBO-HYDROGEN  PRESSURE  IS 
ABOUT  5  LB.  IN  EACH  CASE 


Thickness 
of  Steel 
in  Inches 

Size    of 
Cutting 
Tip 

Lineal  Feet 
Cut  per  Hour 
by    Hand 

Pressure  of 
Cutting  Oxy- 
gen in  Pounds 

Cu.  Ft.  of 
Oxygen    Used 
per  Lineal  Ft. 
of    Cut 

Cu.  Ft.  of  Car- 
bo-Hydrogen 
Used  per  Lineal 
Ft.   of  Cut 

/4" 

1  A 

110 

15 

1 

1 

i/» 

2 

90 

25 

1% 

1 

%* 

2 

75 

32 

2^3 

JK 

1" 

2 

60 

35 

3 

8 

45 

45 

4% 

2/-£ 

2"2 

3 

38 

50 

7 

3/4 

3" 

3 

28 

60 

14 

6 

4' 

3A 

18 

75 

26 

9 

5" 

4 

13 

85 

32 

12 

6" 

4 

11 

100 

40 

13 

7" 

5 

8 

120 

50 

13 

8' 

5-A 

7 

140 

64 

14 

9» 

5-A 

6 

160 

78 

16 

Above  pressures  can  be  increased  at  times  on  various  grades  of  steel 
advantage. 


90 


GAS  TORCH  AND  THERMIT  WELDING 


The  Rego  cutting  torch  is  made  by  the  Bastian-Blessing 
Company,  Chicago.  Like  the  "balanced  pressure"  welding 
torch  made  by  this  concern,  it  is  claimed  that  the  cutting  torch 
cannot  be  made  to  flashback  while  in  use.  Details  of  the 
mechanism  are  shown  in  Fig.  59.  The  tip  is  of  nickel-copper 
composition  and  mates  with  a  ground  joint  to  which  it  is  held 


REINFORCED  TUBES 


NO  FLASHBACK 


i  OXYGEN  VALVE 


FIG.  59. — Rego  Cutting  Torch. 

by  a  union  nut.  The  mixing  chamber  is  easily  renewable.  All 
valves  are  outside  and  easy  to  get  at  for  repacking  or  re- 
grinding.  The  high  pressure  oxygen  valve  seat  is  metal  to 
metal,  and  it  is  controlled  by  a  powerful  spring  and  is  operated 
by  a  long  lever  acting  on  a  plunger,  like  the  valve  of  a  gasoline 
motor.  The  operating  lever  is  easily  locked  so  there  is  no 
strain  on  the  operator's  hand. 


GAS  CUTTING-TORCHES 


91 


Combination  Torches. — Several  companies  make  combina- 
tion welding  and  cutting  torches.     These  usually  consist  of  a 


FIG.  60. — Airco-Vulcan  Combination  Cutting  and  Welding  Torch. 


FIG.  61.— Milburn  "Cut-Weld"  Torch. 


FIG.  61A. — Details  of  Milburn  Torch. 


FIG.  61B.— Details  of  Torch  Tip. 

cutting  attachment  for  the  welding  torch.  As  a  commercial 
proposition,  such  combinations  are  usually  not  to  be  recom- 
mended, but  where  an  operator  occasionally  has  to  shift  quickly 


92  GAS  TORCH  AND  THERMIT  WELDING 

from  welding  to  cutting,  they  may  sometimes  be  used  to  ad- 
vantage. Along  with  their  regular  lines  of  welding-  and  cut- 
ting-torches, the  Air  Reduction  Sales  Co.,  N.  Y.,  put  out  the 
combination  torch  shown  in  detail  in  Fig.  60.  This  is  known 
as  the  Airco-Vulcan  cutting  and  welding  torch,  and  it  well 
illustrates  the  general  principles  of  this  kind  of  a  torch.  The 
main  body  is  that  of  the  regular  Airco-Vulcan  welding  torch. 
The  regular  welding  tip  is  removed  from  A  to  receive-  the 
connection  of  the  special  tip  B.  This  tip  is  connected  at  C 
to  the  high-pressure  oxygen  tube  D.  A  combination  valve  is 
screwed  into  the  torch  body  at  E  in  place  of  the  single  oxygen 
valve  used  for  welding.  This  valve  has  a  passage  at  F  for  the 
preheating  oxygen  and  one  at  G  for  the  cutting  oxygen  that 
goes  out  through  D.  The  preheating  flame  surrounds  the  cut- 
ting jet  as  in  other  regular  cutting  torches,  so  that  an  operator 


FIG.  62.— Torchweld  Gas  Cutting-Torch. 

may  cut  circles  or  angles  without  altering  the  direction  of  the 
torch  body  to  any  extent. 

The  Milburn  Combination  Torch.— The  "Cut-Weld"  torch 
made  by  the  Alexander  Milburn  Co.,  Baltimore,  Md.,  is  shown 
in  Fig.  61.  This  torch  is  made  into  either  a  cutting  or  a 
welding  torch  by  merely  changing  the  tips.  The  illustration 
shows  a  cutting  tip  in  place  and  a  welding  tip  just  at  the  left. 
The  regular  size  is  19  in.  long  and  weighs  2|  Ib.  Details  of  the 
torch,  with  a  cutting  tip  in  place,  are  shown  in  Fig.  61A.  De- 
tails of  a  welding  tip  are  shown  in  Fig.  61B. 

In  tests  in  Washington  before  engineers  of  the  Stone  & 
Webster  Corp.  and  several  government  officials,  a  12  in.  steel 
billet  was  cut  through  in  6J  min.,  which  includes  J  min.  for 
preheating.  A  test  was  made  to  determine  its  resistance  to 
backfire  and  though  the  tip  was  nearly  burned  off,  no  flashback 
took  place.  A  hole  was  also  blown  through  a  5  in.  steel  billet 
in  40  sec.  with  no  flashback. 


GAS   CUTTING-TORCHES  93 

Torchweld  Gas  Cutting-Torch. — The  gas  cutting-torch 
shown  in  Fig.  62  is  made  by  the  Torchweld  Equipment  Co., 
Fulton  and  Carpenter  Sts.,  Chicago,  and  is  known  as  their 
style  15  MC.  It  is  designed  to  use  oxy-acetylene,  oxy-hydrogen, 
or  oxy-hydrocarbon  gases,  such  as  butane,  calorene,  and  the 
like.  Special  tips,  however,  are  needed  for  the  various  gas 
combinations.  An  85-deg.  torch-head  angle  is  standard  but 
70,  50,  35  and  straight  heads  can  be  furnished  when  desired. 

A  one-piece  cutting  tip  is  used  and  the  mixing  chamber  is 
just  back  of  the  torch  head.  A  novel  feature  of  the  construc- 
tion is  that  an  annular  space  is  provided  around  the  mixer  in 
which  a  small  amount  of  gases  accumulate.  Drill  holes  con- 
nect this  space  with  the  gas  passage-way  leading  to  the  tip 
and,  in  case  of  backfire  to  the  mixing  chamber,  the  ignited 
mixture  in  the  annular  space  is  designed  to  blow  out  the  back- 


H.  P  Mzlve  Lerer  ^  p]/a^e  cover 

Acetylene  Tube  .                 H.  P  Valve  Push  Pod.. ^      \       HPffa,rTute  .-P/v<7 
Front  HPOxyaen  Tute-,1'-      H-p^c'^  Rocter n--''-.-.  \,g— ^^/.'-"'    (&PM*'*e  Plunger 


'  Gas  Miter*  :  Rxter  Adjustment 

•'One  Piece  Cutting  Tp 

FIG.  62 A Details  of  Torchweld  Cutting  Torch. 

fire  and  eliminate  the  hazard  of  flashbacks  into  the  flexible 
connecting  hose. 

All  the  gas-tight  seats  in  tips,  needle  valves  and  connec- 
tions, are  of  the  line-contact  type:  In  other  words,  a  convex 
surface  is  brought  into  contact  against  either  a  flat  surface 
or  another  convex  surface.  A  tight  seating  is  thereby  much 
more  easily  obtained  than  by  using  two  flat  surface  contacts. 

One  of  the  difficulties  experienced  with  two-hose  type  cut- 
ting torches  is  the  back  pressure  of  the  acetylene  into  the 
oxygen  hose.  Under  certain  conditions  this  results  in  the 
oxygen  hose  becoming  filled  with  mixed  gases  which  ignite  at 
the  tip  and  a  more  or  less  serious  flashback  into  the  oxygen 
hose  is  unavoidable. 

The  Torchweld  back-pressure  valve  is  claimed  to  prevent 
the  acetylene  from  entering  the  oxygen  hose,  since  a  certain 
pressure  on  the  oxygen  is  necessary  in  order  to  open  this  valve, 


94 


GAS   TORCH   AND   THERMIT   WELDING 


and  as  the  acetylene  pressure  also  tends  to  close  the  valve 
still  tighter. 

Details  of  the  construction  of  this  torch  are  shown  in 
Fig.  62A. 

CUTTING  UNDER  WATER  WITH  A  GAS  TORCH 

A  number  of  torches  have  been  developed  for  cutting  under 
water.  One  of  these  has  been  successfully  used  at  the  Puget 
Sound  Navy  Yard,  Washington  State,  for  some  time,  and  was 
made  by  putting  a  special  hood  over  the  tip  of  a  regular 


FIG.  63. — Underwater  Cutting  Torch.  A  cutting  oxygen  at  65  Ib.  pressure; 
B,  preheating  oxygen;  C,  acetylene  24  Ib.  pressure;  D,  compressed 
air  at  100  Ib.  pressure. 

Davis-Bournonville  cutting  torch  as  shown  in  Fig.  63.  This 
hood  is  pressed  against  the  metal  to  be  cut,  and  air  at  100  Ib. 
pressure  forces  back  the  water  and  protects 'the  flame.  An 
electrical  device  is  used  to  light  the  torch  under  water. 

In  one  case  a  cut  was  made  22  ft.  under  water  by  a  diver, 
who  cut  out  a  piece  19  in.  in  circumference  in  J  in.  ship  plate 
and  rose  to  the  surface  in  6  min.  Six  in.  per  min.  was  the 
rate  cut  on  plate  1  in.  thick.  It  is  claimed  that  this  torch 
will  cut  down  to  200  ft.  under  water. 


CHAPTER  VII 

GAS-PRESSURE  REGULATORS  AND  WORKING 
ASSEMBLIES 

Since  the  gas  pressure  required  in  a  welding  or  cutting 
torch  is  normally  considerably  less  than  that  of  a  generator 
or  storage  cylinder,  some  form  of  pressure  reducer  or  regu- 
lator must  be  used  between  a  torch  and  the  source  of  gas 
supply.  The  regulator  used  must'  not  only  reduce  the  pressures 
to  working  amounts,  but  must  keep  the  gases  supplied  to  the 
torch  at  as  constant  a  pressure  as  possible  regardless  of  the 
variation  in  the  pressures  at  the  sources  of  supply.  This  will 
be  understood  when  it  is  shown  that,  for  example,  oxygen 
at  1800  and  acetylene  at  225  Ib.  pressure  per  sq.in.,  taken  from 
cylinders,  must  be  mixed  in  a  Davis-Bournonville  positive- 
pressure  torch  at  approximate  pressures  of  14  and  6  Ib.  re- 
spectively, when  welding  steel  plate  J  in.  thick.  The  pressure 
in  the  cylinders  will  constantly  decrease  as  the  gases  are  used, 
but  in  order  to  keep  a  correct  neutral  welding  flame  the  gases 
must  be  supplied  to  the  mixing  chamber  of  the  torch  at  the 
approximate  pressures  of  14  and  6  Ib.,  and  keep  close  enough  to 
these  figures  for  long  periods  of  time  to  produce  the  desired 
flame  without  continual  adjusting  of  the  valves.  The  required 
working  pressures  are  determined  by  the  thickness  of  the 
metal  being  operated  upon,  the  make  of  torch,  and  the  size  of 
tip  being  used,  as  tables  already  given  indicate,  but  the  prin- 
ciple remains  the  same  in  any  case. 

Oxweld  Oxygen  Regulators  and  Gages. — The  gas-pressure 
regulators  used  on  welding  and  cutting  apparatus  are  prac- 
tically all  made  on  the  same  general  principle  and  vary  only 
in  minor  details  of  construction.  An  Oxweld  oxygen  regulator 
shown  in  Fig.  64  will  serve  to  illustrate  the  construction  in 
general.  The  principal  parts  of  a  regulator  of  this  kind  are 
the  body  proper,  regulating  or  shut-off  valve,  diaphragm, 

95 


96 


GAS  TORCH   AND   THERMIT  WELDING 


pressure-adjusting  spring  and  pressure-indicating  gages.  As 
a  general  rule  all  regulators  have  two  pressure-indicating 
gages,  one  on  the  intake  or  high-pressure  line,  and  one  on  the 
outlet,  or  low-pressure  line.  The  gage,  however,  on  the  low- 
pressure  acetylene  line  is  sometimes  omitted  when  using  a  low- 
pressure,  or  injector,  torch  on  account  of  the  low  pressure  at 
which  the  acetylene  is  used. 

In  the  illustration  given,  a  dust  or  protecting  plug  is  shown 
screwed  into  the  connecting  nut  on  the  intake  tube.     This  is 


FIG.   64. — Details  of  Oxweld  Oxygen-Pressure  Regulator. 

of  course  removed  when  attaching  the  regulator  to  the  supply 
pipe  or  valve.  The  arrows  indicate  the  flow  of  the  gas  when 
free  to  move  from  the  intake  to  the  outlet.  Following  these 
arrows  it  will  be  seen  the  gas  enters  the  intake  and  flows  into 
the  vertical  passage  A  where  it  goes  upward  to  the  high-pres- 
sure gage  B,  which  indicates  the  pressure  of  the  supply  line. 
The  gas  also  flows  downward  in  the  same  passage  until  it 
reaches  the  monel-metal  nozzle  of  the  regulating  valve  at  C. 
It'  the  screw  D  is  turned  to  the  left  far  enough  to  prevent 
spring  E  from  forcing  the  diaphragm  F  inward  against  the 
sliding  sleeve,  then  spring  G  will  keep  the  seat  H  solidly 


GAS-PRESSURE  REGULATORS  97 

against  the  nozzle  C  and  no  gas  will  enter  the  body  of  the 
regulator  beyond  the  passage  A.  However,  if  the  screw  D 
has  been  run  inward  far  enough  to  put  a  tension  on  spring 
E  the  diaphragm  F  will  be  forced  inward  and  the  regulating 
valve  will  be  held  open.  Gas  will  then  flow  into  the  diaphragm 
chamber  /  until  the  pressure  of  the  gas  against  the  diaphragm 
overcomes  the  pressure  of  spring  E.  This  allows  spring  G 
to  close  the  regulator  valve  and  stop  the  flow  of  gas.  The 
flow  is  not  usually  actually  stopped  when  the  torch  is  in  use, 
since  the  flow  of  gas  and  the  pressure  of  the  spring  E  will 
be  so  balanced  as  to  allow  just  enough  gas  to  enter  to  keep 
the  pressure  practically  constant  in  the  outlet  line.  The  farther 
the  screw  D  is  run  in  the  more  tension  is  put  on  the  spring  E 
and  the  diaphragm  F,  and  consequently  the  higher  will  be  the 
gas  pressure  in  the  outlet  line  to  the  torch.  From  this  it  will 
be  seen  that  any  desired  pressure  within  the  capacity  of  the 
regulator  can  be  obtained,  and  maintained,  in  the  outlet  to 
the  torch  by  simply  adjusting  the  screw  D.  The  diaphragm 
used  on  a  regulator  of  this  kind  may  be  made  of  reinforced 
sheet  rubber,  phosphor  bronze  or  other  composition  metal  that 
will  not  corrode  or  break  easily. 

The  regulators  used  for  other  gases  differ  but  little  from 
those  used  for  acetylene  or  oxygen,  and  often  the  same  regu- 
lators may  be  used  provided  the  pressures  required  are  within 
the  range  of  the  regulator  in  question.  An  oxygen  regulator 
for  cutting  work  should  be  built  heavier  and  deliver  a  larger 
amount  of  gas  than  one  used  for  welding  on -account  of  the 
higher  pressure  required  and  greater  gas  consumption.  In 
using  acetylene  from  a  pressure  generator  it  is  good  practice 
to  have  an  acetylene  line  regulator  as  well  as  one  for  each 
operator's  torch  line. 

The  Oxweld  oxygen  gages  used  when  welding  arc  made 
to  register  from  0  to  2700  Ib.  per  sq.in.  on  the  high  pressure 
side  and  from  0  to  60  Ib.  per  sq.in.  on  the  low-pressure  side, 
as  shown  in  Fig.  65.  It  will  be  seen,  by  examination,  that  the 
outer  scale  on  the  high-pressure  gage  shows  the  pressure  in 
pounds  and  the  inner  scale  indicates  the  percentage  of  gas  in 
the  cylinder.  That  is,  for  example,  if  the  gage  hand  points  to 
600  Ib.  there  would  be  approximately  35  cu.ft.  of  oxygen  left 
in  the  cylinder,  providing  a  100-cu.ft.  cylinder  was  being  used. 


98  GAS  TORCH  AND  THERMIT  WELDING 

If  it  was  a  200-cu.ft.  cylinder  the  amount  left  would  be  ap- 
proximately 70  cu.ft.  As  has  been  pointed  out  elsewhere, 
these  figures  cannot  be  taken  as  showing  the  exact  amount  of 
gas  in  the  cylinder  except  under  certain  conditions,  but  they 
are  sufficiently  accurate  for  all  ordinary  purposes. 

For  cutting  purposes  the  Oxweld  oxygen  regulator  shown 
in  Fig.  66,  is  fitted  with  the  same  gage  on  the  high-pressure 


FIG.  65. — Oxweld  Oxygen  Welding  Regulator. 

side  as  for  welding,  but  on  the  low-pressure  side  the  gage 
registers  up  to  200  Ib.  per  sq.in.  Their  acetylene  regulator 
is  only  supplied  with  a  350-lb.  gage  on  the  high-pressure  side, 
as  shown  in  Fig.  67.  This  is  because  of  the  fact  that  the 
Oxweld  torches  use  acetylene  at  about  1-lb.  pressure  at  all 
times.  However,  if  required,  two  gages  may  be  used  as  in  all 
other  makes. 


GAS-PRESSURE   REGULATORS  99 

Other  Regulators  and  Gages. — A  Davis-Bournonville  oxygen 
regulator  with  gages  is  shown  in  Fig.  68.  This  indicates  from 
0  to  3000  Ib.  per  sq.in.  on  the  high-pressure  side  and  up  to 
400  Ib.  on  the  low-pressure  side.  On  the  dial  of  the  high- 
pressure  gage  are  three  rows  of  figures.  The  outer  row  shows 
the  pressure  per  sq.in. ;  the  middle  row,  the  cubic  feet  of 
contents  for  both  100-  and  200-ft.  cylinders;  the  inner  row 
indicates  the  cubic  feet  of  contents  for  250-cu.ft.  cylinders  at 


FIG.   66. — Oxweld  Oxygen  Cutting  Regulator. 

various  pressures.  Details  of  a  regulator  used  for  acetylene  are 
shown  in  Fig.  69.  This  is  practically  the  same  in  construction 
as  the  oxygen  regulator.  The  numbers  shown  are  list  numbers 
of  the  parts,  and  are  very  convenient  for  ordering  broken  or 
damaged  parts  at  any  time.  The  regulator  acetylene  gages 
register  up  to  400  Ib.  on  the  high-pressure  side  and  up  to 
300  Ib.  on  the  low-pressure  side. 

An  oxygen  regulator  made  by  the  General  Welding  and 
Equipment  Co.,  attached  to  a  cylinder  is  shown  in  Fig.  70. 


100 


GAS   TORCH   AND   THERMIT   WELDING 


At  the  right  and  almost  opposite  from  where  the  regulator 
is  attached,  is  a  projection  which  is  a  fusible  blow-off  plug 
required  on  all  cylinders  by  the  Interstate  Commerce  Com- 
mission, to  provide  for  the  escape  of  the  gas  in  case  the  cylinder 
should  be  overheated  and  the  pressure  become  so  great  as  to 
be  liable  to  cause  an  explosion.  This  illustration  clearly  shows 
the  kind  of  valve  that  is  used  on  an  oxygen  cylinder.  It  is 
completely  covered  with  a  metal  cap  screwed  onto  the  threads 


FIG.  67. — Oxweld  Acetylene  Regulator. 

siiown  at  the  top  of  the  cylinder.  The  cap  protects  the  valve 
and  prevents  it  being  broken  off  or  damaged  when  the  cylinder 
is  handled  or  shipped.  In  using  gas  cylinders  under  working 
conditions  it  is  advisable  to  have  them  placed  on  a  portable 
truck  made  for  the  purpose,  or  else  fastened  in  some  way  so 
that  they  cannot  be  tipped  over.  This  will  often  prevent 
needless  damage  to  the  apparatus  and  sometimes  avoid  serious 
accidents.  It  should  always  be  kept  in  mind  that  gases  under 


GAS-PRESSURE 


/,  101 


from  225-  to  1800-lb.  pressure  per  square  inch  are  not  to  be 
trifled  with. 

Tank  and  Hose  Colors. — Oxygen  cylinders  of  different  con- 
cerns do  not  have  a  uniform  color,  but  are  usually  painted 
gray  and  green,  red,  yellow  or  dark-green.  Acetylene  cylinders 
are  generally  painted  black  and  have  a  plate  on  them  giving 


FIG.  68. — Davis-Bournonville  Oxygen  Regulator. 

the  quantity  of  gas  the  tank  contains.  Practice  also  varies 
as  to  the  color  of  hose  used  to  connect  to  the  torches.  Common 
colors  are  black  hose  for  acetylene  and  red  hose  for  oxygen, 
although  sometimes  oxygen  hose  is  black  and  the  acetylene 
red.  In  making  all  hose  or  valve  connections,  they  must  be 
carefully  blown  out  to  remove  dust  or  any  foreign  substance. 
This  is  especially  important  on  new  hcse  which  is  almost  sure 


102  ^  GAS  TORCH  .AND   THERMIT  WELDING 

2*\l  tfj^r*.      i    :  • 

to  contain  considerable  bloom  left  from  the  vulcanizing.  In 
addition  to  their  specific  color,  acetylene  cylinder  valves  are 
often  threaded  left  hand,  as  a  safeguard  against  making  the 
wrong  connections. 


2426 


I5ZC 


FIG.  69. — Details  of  Davis-Bournonville  Acetylene-Pressure   Regulator. 

ID  making  oxygen  connections  it  must  be  remembered  that 
under  no  circumstances  should  oil  or  grease  be  used  on  the 
oxygen  regulator  or  cylinder  valve.  This  is  highly  important 


GAS-PRESSURE   REGULATORS 


103 


as  oxygen  under  pressure  coming  in  contact  with  oil  or  grease 
causes  spontaneous  combustion  which  might  easily  result  in 


FIG.  70. — Kegulator  Attached  to  a  Gas-Cylinder  Valve. 


FIG.   71. — Regulator  and  Cylinder-Connection  Adapters 

a  serious  accident.     If  a  lubricant  of  any  kind  is  needed  a 
little  glycerine  may  be  used. 

Regulator  Adapters. — No  make  of  regulator  is  so  made  as 


104  GAS  TORCH   AND   IHEilMIT   WELDING 

to  be  regularly  interchangeable  with  all  makes  of  gas  cylinders, 
since  the  sizes  and  threads  used  on  different  makes  of  cylinder 
connections  vary  considerably.  For  this  reason  adapters  must 
be  used  in  many  cases.  Some  of  these  are  shown  in  Fig.  71. 
Care  should  therefore  be  taken  to  make  sure  that  the  regulator 
will  fit  the  cylinder  connections  properly,  or  that  the  right 
adapter  is  used.  If  a  regulator  connection  or  an  adapter  does 
not  start  readily,  it  should  not  be  forced  as  it  is  probably  the 
wrong  diameter  or  the  thread  may  be  of  the  opposite  kind — 
that  is  right-  or  left-hand.  Also  be  sure  that  an  adapter  with 
a  round  or  conical  seat  is  not  used  on  a  flat  seat,  nor  a  round 
seat  on  a  conical  one  or  one  not  made  for  it.  Adapters  are 
made  of  soft  brass  and  careless  handling  will  cause  a  leaky 
joint.  In  ordering  adapters  the  make  of  regulator  used  should 
be  specifically  stated,  and  also  the  make  of  cylinder  on  which 
it  is  to  be  used,  as  well  as  whether  it  is  for  oxygen,  acetylene, 
hydrogen  or  other  gas. 

Connecting  Up  and  Lighting  the  Torch. — In  order  to  make 
perfectly  clear  to  the  reader  how  to  connect  up  a  welding 
apparatus  for  the  first  time,  an  Imperial  welding  outfit  is 
shown  in  Fig.  72.  First  remove  the  protecting  cap  from  the 
oxygen  cylinder,  and  then  open  valve  A  very  slightly.  This 
is  to  blow  out  any  dust  and  to  insure  the  free  working  of  the 
valve  after  the  regulator  is  attached,  which  otherwise  might 
be  injured  by  the  sudden  "rush  of  gas  into  it.  In  doing  this, 
stand  on  the  side  opposite  from  the  opening  so  that  the  gas 
will  blow  away  from  you.  Always  keep  this  in  mind  when 
blowing  out  the  valve  on  any  cylinder.  Now  take  the  regulator 
and  turn  the  handle  B  to  the  left  until  it  turns  freely,  so  as 
to  be  clear  of  the  diaphragm.  Next  make  sure  the  connection 
at  C  is  clean  and  free  from  dirt  and  fits  properly  or  has  the 
right  adapter,  then  screw  it  up  using  judgment  with  the 
wrench  so  as  not  to  break  anything.  With  the  valve  at  D 
closed,  slowly  open  the  valve  A  as  far  as  it  will  go,  using  some 
force  with  the  hand  to  insure  that  it  is  really  backed  up 
against  the  gland  solidly.  This  is  to  aid  in  preventing  the 
high-pressure  oxygen  from  escaping  around  the  valve  stem. 
When  the  valve  is  fully  opened,  the  gage  E  will  indicate  the 
cylinder  pressure  which  on  a  new  one  will  be  close  to  1800 
Ib.  Now  put  on  the  oxygen  hose  at  F  and  then  turn  the 


GAS-PRESSURE  REGULATORS 


105 


handle  B  to  the  right  until. about  5  Ib.  are  registered  on  gage  G. 
Then  open  valve  to  D  so  as  to  blow  any  dirt  or  bloom  out  of  the 
hose.  The  valve  D  is  then  closed  and  the  hose  connected  to  the 
torch  at  H.  The  valve  /  on  the  torch  may  now  be  closed,  the 
valve  D  opened,  and  the  handle  B  screwed  in  until  the  gage 
G  registers  the  proper  pressure  for  the  proposed  welding  job, 


CETYLENE 


FIG.  72. — Imperial  Welding  Outfit  Connected  to  Tanks. 

as  indicated  in  the  pressure  table  for  the  make  of  torch  being 
used.  The  various  connections  should  then  be  carefully  gone 
over  with  soapy  water  to  test  for  leaks.  Never  use  a  flame 
on  the  oxygen  or  any  other  gas  tank  even  though  oxygen  alone 
is  not  inflammable.  Assuming  that  the  proper  tip  has  been 
placed  in  the  torch  for  the  thickness  of  metal  to  be  welded, 
the  torch  valve  7  may  now  be  opened  fully  and  the  handle 


106  GAS  TORCH  AND  THERMIT  WELDING 

screwed  in  until  the  gage  G  registers  about  2  Ib.  over  the 
pressure  given  in  the  table.  This  is  to  allow  for  the  variation 
in  cylinder  pressure  as  the  gas  is  used.  The  torch  valve  I  is 
next  closed,  and  it  is  also  well  to  close  the  valve  D  as  a  safe- 
guard before  attaching  the  acetylene  hose. 

The  acetylene  regulator  and  tank  are  now  connected  up 
in  exactly  the'  same  way,  except  that  the  acetylene  tank  valve 
/,  must  be  only  opened  one  full  turn.  (On  one  make  of 
cylinder  the  directions  say  two  turns,  so  the  operator  should 
read  the  directions  on  the  tank  carefully.)  The  hose  is  con- 
nected at  K  and  blown  out  to  remove  any  dirt,  care  being 
taken  that  no  flame  is  near.  '  It  is  then  connected  to  the  torch 
at  L,  and  tests  are  made  for  leaks  as  before  with  the  valve  M 
open  and  the  torch  valve  N  closed.  The  torch  valve  N  is  next 
slightly  opened  and  the  issuing  gas  lighted.  The  valve  is 
then  fully  opened,  and  if  the  gage  O  shows  any  appreciable 
drop,  the  handle  P  should  be  turned  until  the  gage  registers 
about  2  Ib.  above  the  amount  shown  by  the  table.  The  resulting 
flame  from  the  burning  acetylene  will  be  long,  white,  smoky, 
and  of  comparatively  low  temperature.  The  torch  valve  N 
may  then  be  manipulated  until  the  pressure  blows  the  flame 
from  1/18  to  1/4  in.  away  from  the  tip,  the  distance  depending 
on  the  size  of  the  tip  being  used.  This  can  only  be  judged 
properly  by  experience.  The  oxygen  may  now  be  turned  on 
slowly.  The  flame  will  gradually  reduce  in  size,  the  outer  end 
or  envelope  becoming  less  luminous  and  the  part  near  the  torch 
tip,  known  as  the  cone,  assuming  a  clear  outline  without  any 
ragged  edges.  When  this  is  obtained,  turn  off  the  oxygen 
slowly  until  a  shadowy  point  shows  from  the  cone.  Then  with 
extreme  care  turn  on  the  oxygen  again  until  this  shadowy 
point  just  disappears.  This  is  the  so-called  neutral  flame,  and 
is  neither  oxidizing  nor  carbonizing. 

From  time  to  time,  while  at  work,  the  operator  should  test 
the  flame  as  just  outlined,  as  a  slight  excess  of  oxygen  pressure 
will  not  readily  show  in  the  flame  and  can  only  be  detected 
by  this  method.  It  will  be  found  in  practice,  as  a  rule  after 
the  pressures  have  been  set  on  the  gages,  that  all  regulation 
necessary  for  the  smaller  sizes  of  tips  may  be  made  with  the 
torch  valve,  but  that  on  the  regular  sizes  it  is  often  advisable 
to  readjust  at  the  regulators.  It  will  be  well  to  repeat  here, 


GAS-PKESSURE   REGULATORS 


107 


for  the  benefit  of  the  beginner,  that  all  indicated  table  pressures 
are  only  approximate  and  good  only  for  the  make  of  torch 
mentioned  in  connection  with  them. 

Characteristics  of  the  Oxy- Acetylene  Welding  Flame.— 
The  chart  shown  in  Fig.  73  will  serve  to  illustrate  the  looks 
of  the  oxy-acetylene  flame  as  far  as  it  is  possible  to  do  on 
paper:  A  shows  acetylene  turned  on  with  sufficient  pressure, 
so  that  it  blows  away  from  the  tip.  This  space  depends  upon 
the  size  of  tip  being  used.  B  shows  oxygen  partly  turned 
on,  united  with  the  acetylene.  The  flame  has  begun  to  assume 
two  different  shapes  and  two  different  colors.  The  center 


D 


FIG.  73. — Characteristics  of  the  Oxy-Acetylene  Welding  Flame. 

flame  is  white  and  is  shaped  somewhat  like  a  rosebud.  Not 
enough  oxygen  has  yet  been  given  the  acetylene  and  the  flame 
is  called  carbonizing.  Such  a  flame  will  leave  the  metal  brittle 
and  hard.  C  is  the  neutral  welding  flame.  The  rosebud  cone 
of  the  upper  figure  has  become  blunt,  with  no  ragged  edges 
and  of  a  beautiful  blue-white  color.  D  is  an  oxidizing  flame — 
ruinous  to  welding.  This  is  obtained  by  turning  on  too  much 
oxygen  and  the  cone  has  become  shorter,  of  a  darker,  dirtier 
blue,  and  is  more  pointed.  This  view  is  exaggerated.  The 
utmost  care  is  necessary  to  guard  against  this  flame.  Even  a 
slight  excess  of  oxygen  is  detrimental,  as  it  will  "burn"  the 
metal. 

To  stop  work  temporarily,  first  close  the  oxygen  valve  in 


108  GAS  TORCH  AND  THERMIT  WELDING 

the  torch  and  then  the  acetylene  valve.  To  stop  work  per- 
manently, first  close  the  torch  valves  in  the  order  just  given, 
then  screw  back  both  regulator  handles  until  they  are  free 
of  the  diaphragms.  Then  shut  off  the  tank  valves  tightly. 

In  case  of  a  flashback,  always  close  the  oxygen  valve  in- 
stantly, then  the  acetylene  valve,  after  which  the  torch  head 
may  be  cooled  in  a  bucket  of  water.  It  should  always  be  kept 
in  mind  never  to  turn  on  the  gas  at  the  cylinder  with  the 
regulating  screw  tiglit,  as  this  puts  spring  tension  en  the 
diaphragm  and  allows  the  gas  from  the  cylinder  to  enter  the 
body  of  the  regulator  very  suddenly  (because  the  plunger  of 
the  valve  is  away  from  the  seat)  and  as  the  sudden  pressure 
strikes  the  diaphragm,  the  plunger  is  thrown  violently  against 
the  seat,  often  causing  the  seat  to  become  cracked  or  broken. 

With  the  motor  of  an  automobile  racing,  you  wouldn't 
throw  the  gears  in  mesh  for  high  speed  direct  from  neutral 
and  attempt  to  start  away  from  the  curb — not  if  you  wanted 
to  keep  your  automobile  very  long — yet  turning  on  the  oxygen 
with  the  spring  tension  on  the  regulator  has  about  the  same 
effect  on  the  regulator. 

Bear  in  mind  that  the  regulator  is  a  steadying  device — that 
the  diaphragm  is  the  balance  between  the  high  pressure  of 
the  cylinder  gas  and  the  spring  tension  and  that  at  all  times 
the  movement  of  this  diaphragm  should  be  slow — never  violent. 

The  low-pressure  gage  is  a  positive  index  of  regulator 
trouble.  If  you  are  operating,  say  at  15  lb.,  and  after  shutting 
off  the  valve  on  the  torch,  the  hand  on  the  dial  keeps  moving 
to  25  or  30  or  40  lb.  without  stopping,  it  means  that  the  seat 
is  damaged — that  the  high  pressure  of  the  cylinder  is  leaking 
past  the  plunger  of  the  valve  and  the  regulator  should  be 
immediately  sent  back  to  the  factory  for  repairs.  Only  by 
violating  some  of  the  rules  previously  given  would  you  be 
likely  to  damage  this  seat ;  but  once  damaged,  it  should  be 
immediately  repaired. 

It  will  be  noticed  that  two  acetylene  tanks  are  shown  in 
Fig.  72.  These  represent  the  two  types  in  common  use.  The 
one  in  the  middle  is  the  type  furnished  by  both  the  Air  Re- 
duction Sales  Co.  and  the  Commercial  Acetylene  Co.,  while 
the  tank  at  the  left  is  furnished  by  the  Prest-0-Lite  Co.  In 
the  first  named  the  regulator  stands  out  at  right  angles,  and 


GAS-PRESSURE   REGULATORS 


109 


in  the  other  it  stands  up  as  shown.  The  valve  in  the  Prest- 
0-Lite  cylinder  differs  considerably  from  the  others  as  will 
be  seen  in  Fig.  74.  In  this  illustration  the  valve  is  shown  at 
A,  the  valve  wrench  at  B,  the  packing  nut  of  the  valve  at  0, 
and  the  union  nut  by  which  the  regulator  is  attached,  at 
D.  E  is  the  high-pressure  gage,  F  the  low-pressure  gage,  G, 
the  regulator,  H  the  pressure-adjusting  handle,  /  the  outlet  and 
J  the  hose  nipple. 

Lighting  the  Oxweld  Low-Pressure  Torch. — The  directions 
given  by  the  Oxweld  company  for  the  lighting  of  their  low- 
pressure  or  injector  torches,  differ  slightly  from  the  foregoing, 


FIG.  74. — Prest-O-Lite  Acetylene-Regulator  Assembly. 

so  they  will  be  quoted  here,  starting  from  where  the  gases 
have  been  turned  into  the  high-pressure  sides  of  the  regulators, 
which  is  the  same  as  already  outlined : 

First,  connect  the  oxygen  hose  from  the  oxygen  regulator 
to  the  hose  connection  on  the  torch  marked  oxygen.  Likewise 
connect  the  acetylene  hose  to  the  torch  valve  marked  acety- 
lene. Then  select  the  proper  welding  head  or  tip  that  is  to 
be  used  according  to  the  chart  or  table  furnished,  and  screw 
it  carefully  into  the  torch.  Turn  on  the  oxygen  by  means  of 
the  handscrew  of  the  oxygen  regulator  until  the  pressure  on 
the  small  gage  is  as  given  on  the  chart.  Be  sure  that  when 
this  is  done  the  oxygen  valve  on  the  torch  is  open.  Then  close 


110  GAS  TORCH  AND  THERMIT  WELDING 

this  valve.  Open  the  acetylene  valve  on  the  torch.  Then  turn 
the  handscrew  on  the  acetylene  regulator  to  the  right  until 
acetylene  is  passing  through  the  torch.  Then  close  the  acety- 
lene valve  on  the  torch. 

The  apparatus  is  now  ready  for  use,  and  the  gases  are 
further  regulated  when  necessary  by  adjusting  the  valves  on 
the  torch  itself.  Open  the  acetylene  valve  entirely.  Open  the 
oxygen  valve  slightly.  Then  light  the  gases.  After  lighting 
the  gases,  open  the  oxygen  valve  wide;  adjust  the  flame  by 
turning  the  acetylene  valve  to  the  right  until  a  neutral  flame 
is  produced. 

When  the  job  is  finished  and  you  want  to  shut  off  the  torch 
for  a  short  time,  release  or  turn  the  handscrew  on  both  oxygen 
and  acetylene  regulators  to  the  left  until  the  flame  on  the  torch 
goes  out.  Then  close  the  torch  valves.  When  work  is  completed 
for  the  day  and  the  apparatus  is  to  be  put  away,  first  close 
the  acetylene  valve,  then  the  oxygen  valve  of  the  torch.  Then 
turn  off  the  valves  on  both  cylinders.  Then  open  the  valves 
on  the  torches  until  all  the  gas  in  the  regulators  and  hose 
passes  out  of  the  torch  into  the  air.  Then  turn  the  handscrew 
of  both  regulators  to  the  left  until  loose.  Then  disconnect 
the  oxygen  and  acetylene  regulators  from  the  cylinders.  Each 
regulator  has  a  dust  plug  which  is  to  be  put  on  its  cylinder 
connection  during  all  the  time  the  regulators  are  not  con- 
nected to  the  cylinders. 

Place  the  regulators  and  torches  with  wrenches,  goggles, 
heads,  and  tips  in  their  proper  place  so  that  they  will  be 
safe  and  protected  from  dust,  dirt,  and  rough  handling.  Roll 
up  the  hose  and  put  it  in  the  case  or  tool  box  where  it  belongs. 

Chemistry  of  the  Oxy-Acetylene  Flame. — According  to  the 
Prest-0-Lite  company,  the  chemistry  of  the  oxy-acetylene 
flame  is  as  follows:  Acetylene  (C2H2)  is  composed  of  carbon 
(C)  and  hydrogen  (H').  On  combustion,  the  carbon  combines 
with  oxygen  to  form  carbon  dioxide  (C02)  and  the  hydrogen 
combines  with  oxygen  to  form  water  vapor  (H20).  This  takes 
place  in  the  following  manner: 

When  the  gases  issue  from  the  torch  into  the  welding  flame, 
the  acetylene  immediately  dissociates;  in  other  words,  it  splits 
up  into  carbon  and  hydrogen  which  in  combination  with  oxygen 
form  respectively  carbon  dioxide  and  water  vapor.  In  con- 


GAS-PRESSURE   REGULATORS 


111 


sequence  of  the  high  flame  temperature  (6300  deg.  F.)  the 
water  vapor  formed  by  this  primary  combustion  is  immediately 
dissociated  into  hydrogen  and  oxygen.  The  oxygen  assists  in 
the  burning  of  the  carbon  while  the  hydrogen  (which  can  only 
combine  with  oxygen  at  a  temperature  below  4000  deg.  F.) 
passes  away  from  the  high-temperature  zone  and  combines 
with  the  oxygen  of  the  atmosphere  at  the  outer  blue  part  of 


FIG.  75. — Imperial  Three-Way  Gas  Outfit. 

the  flame,  where  the  temperature  is  sufficiently  low  to  permit 
it.  The  result  of  this  is  that  the  inner  or  welding  cone  of  the 
flame  is  protected  by  a  shield  of  free  hydrogen  which  prevents 
loss  of  heat  and  also  tends  to  protect  the  weld  from  oxida- 
tion. The  temperature  of  the  oxy-acetylene  flame  is  approxi- 
mately 6300  deg.  F.,  at  the  hottest  part  of  the  flame,  which  is 
the  tip  of  the  inner  white  cone.  The  effect  of  this  tremendous 
heat  at  the  point  of  treatment  is  to  bring  the  metal  very 


112  GAS   TORCH  AND   THERMIT   WELDING 

rapidly  to  a  molten  state  so  that  it  flows  together  and  mixes 
thoroughly  with  the  proper  quantity  of  metal  added  by  the 
operator. 

The  molten  mass  thus  formed  does  not  merely  cement  two 
pieces  of  metal  together — it  fuses  them  into  one  uniform  mass. 

Characteristics  of  Other  Gas  Flames. — The  way  an  Imperial 
three-way  outfit  is  connected  up  is  shown  in  Fig.  75.  The 
procedure  is  along  the  same  lines  as  outlined  for  the  oxy- 
acetylcne  work.  This  combination  of  oxygen,  acetylene  and 
hydrogen  gives  a  more  visible  flame  and  a  sharper  cone  than 
oxy-hydrogen  alone  does.  Only  a  small  percentage  of  acetylene 
is  necessary  to  give  the  sharper  cone  but  the  flame  retains 
the  clearness,  beauty  and  good  qualities  of  the  oxy-hydrogen 
flame.  The  percentage  of  acetylene  may  be  varied  according 
to  the  thickness  and  character  of  the  metal  being  welded,  so 
that  the  degree  of  heat  and  amount  of  carbon  can  thereby 
be  regulated  to  meet  different  conditions.  The  approximate 
pressures  to  be  used  for  the  three  gases  for  average  work, 
will  be  found  in  a  previously  given  table.  The  combination 
will  produce  a  heat  of  about  5000  deg.  F. 

The  oxy-hydrogen  flame  will  produce  a  much  softer  weld 
than  oxy-acctylene  if  properly  iised,  but  its  lower  heat  and 
the  fact  that  the  cone  is  not  concentrated  in  a  sharp  needle 
point,  which  allows  the  heat  to  radiate  more,  are  drawbacks 
when  heavy  welding  is  attempted.  The  low  visibility  of  the 
oxy-hydrogen  flame  also  makes  it  difficult  to  regulate  properly, 
and  an  operator  requires  considerable  experience  before  he 
can  become  proficient  in  its  use.  As  has  been  already  men- 
tioned, however,  its  long  flame  makes  it  very  desirable  to  use 
for  the  preheating  flame  in  a  cutting  torch,  especially  on 
heavy,  thick  work.  In  welding  with  the  oxy-hydrogen  flame, 
the  torch  has  to  be  held  farther  away  from  the  work  than 
with  the  oxy-acetylene  torch  on  account  of  the  longer  and 
less  concentrated  flame.  "When  a  black  spot  appears  in  the 
weld  it  shows  that  the  torch  is  being  held  too  close. 

The  Oxy-Hydrogen  Flame. — The  characteristics  of  the  oxy- 
hydrogen  flame  are  shown  in  Fig.  76.  In  this  illustration, 
which  is  as  clear  as  a  flame  can  be  represented  on  paper,  the 
different  flames  are  outlined  as  follows:  E  shows  the  hydro- 
gen turned  on  with  sufficient  pressure  so  that  it  blows  away 


GAS-PRESSURE   REGULATORS 


113 


from  the  end  of  the  tip.  The  distance  will  vary  from  about 
Vie  to  */4  i11-  according  to  the  size  of  tip  and  pressures  used. 
F  shows  the  oxygen  turned  on.  A  narrow,  light-blue  streak 
appears  in  the  center  of  the  hydrogen  mantle.  This  is  the 
desired  neutral  flame.  G  is  an  oxidizing  flame  that  will  burn 
the  metal.  The  oxygen  valve  should  be  gradually  closed  until 
the  excess  of  oxygen  disappears. 

Where  hydrogen  and  compressed  air  are  used  as  is  done  in 
preheating  work,  light  welding,  or  lead  burning,  the  flame 
closely  resembles  that  of  the  oxy-hydrogen  flame.  The  appear- 


Light 
blue  - 


FIG.  76.— Characteristics  of  the  Oxy-Hydrogen  Flame. 

ance  of  the  hydrogen-air  flame  is  indicated  in  Fig.  77.  E 
shows  the  hydrogen  turned  on  with  pressure  enough  to  blow 
the  flame  away  from  the  tip,  the  distance  being  about  the 
same  as  already  given.  /  shows  the  compressed  air  turned  on 
and  a  dark  streak  of  mixed  air  and  hydrogen  appears  in  the 
center.  This  is  the  neutral  flame.  J  is  the  oxidizing  flame. 

In  general  the  air  pressure  used  for  this  flame  is  close  to 
that  where  oxygen  is  used. 

The  Oxy-IUuminating  Gas  Flame. — The  flame  produced  by 
mixing  oxygen  and  coal  gas,  or  natural  gas,  is  suitable  only 
for  lead  burning,  preheating,  very  light  steel  welding,  light 
cast-iron  welding,  or  the  welding  of  light  brass  or  aluminum. 


114 


GAS  TORCH  AND  THERMIT  WELDING 


The  characteristics  are  shown  in  Fig.   78.     K  shows  the  gas 
turned  on  full  force  enough  to  slightly  blow  the  yellow  flame 


FIG.  77. — Characteristics  of  the  Hydrogen-Compressed- Air  Flatae. 


Purple- 


FIG.  78. — Characteristics  of  the  Oxygen  Illuminating  Gas  Flame. 

away  from  the  tip.  L  is  the  neutral  flame  produced  by  turn- 
ing on  the  oxygen.  The  cone  is  narrow  and  about  J  in.  long, 
of  a  beautiful  purple  color  in  a  pure-blue  outer  mantle.  M 


GAS-PRESSURE   REGULATORS  115 

shows  too  much  oxygen.  The  cone  has  turned  a  reddish  color. 
The  oxygen  must  be  decreased  until  the  sharp  purple-colored 
cone  appears.  In  using  oxygen  and  illuminating  gas,  a  water 
seal  should  be  used  on  the  gas  line  to  assist  in  purifying  the 
gas  and  to  prevent  the  entrance  of  any  flame,  or  oxygen  which 
might  form  an  explosive  mixture. 

Where  acetylene  and  compressed  air  are  used,  as  is  some- 
times done  for  certain  preheating  or  welding  jobs,  the  flame 
characteristics  closely  resemble  the  oxy-acetylene  flame. 

In  order  to  obtain  the  best  results,  special  tips  should  be 
used  in  the  torch  for  the  different  gas  combinations  described. 
These  can  usually  be  promptly  supplied  by  the  makers  of  any 
of  the  torches  on  the  market. 


CHAPTER  VIII 
GAS-TORCH  WELDING  AND  CUTTING  OUTFITS 

Cutting  torches  are  lighted  in  the  same  way  as  are  the 
welding  torches.  In  most  cases,  however,  the  oxygen  pressure 
to  the  preheating  flame  has  to  be  several  pounds  higher,  on 
account  of  the  drop  after  the  cutting  jet  is  turned  on.  The 
apparatus  used  for  cutting  is  also  set  up  in  the  same  way  as 
for  welding,  as  will  be  seen  from  the  typical  Oxweld  cylinder 
outfit  shown  in  Fig.  79. 

"Where  large  amounts  of  oxygen  are  used  for  cutting  or 
welding,  it  is  well  to  have  a  centralized  source  of  supply  so 
arranged  that  the  flow  of  oxygen  need  not  be  interrupted  at 
any  time,  and  will  be  ample  for  all  demands.  For  this  pur- 
pose, the  Oxweld  company  has  designed  the  oxygen  cylinder 
manifold  shown  in  Fig.  80.  Oxygen  from  this  manifold 
may  be  piped  anywhere  in  a  plant  exactly  the  same  as  the 
acetylene  is.  It  eliminates  the  enormous  amount  of  handling 
necessary  in  supplying  full  cylinders  and  removing  the 
empty  ones  from  each  individual  station.  The  manifolds  are 
so  arranged  that  each  half  operates  independently,  making 
it  possible  to  provide  an  uninterrupted  supply  of  oxygen. 
If  desired,  both  halves  may  be  operated  in  unison.  These 
manifolds  are  made  in  four  sizes  to  accommodate,  6,  10,  20 
and  30  cylinders  respectively.  Each  manifold  will  handle 
cylinders  of  either  100-  or  200-cu.ft.  capacity  without  any 
additional  change  or  adjustment.  They  have  two  constant 
pressure  regulators,  one  of  which  is  for  relief  service. 

Acetylene  cylinder  couplers  or  manifolds  are  used  for  the 
same  reason  as  are  those  for  oxygen.  A  number  of  Prest-O- 
Lite  acetylene  cylinders  coupled  together  is  shown  in  Fig.  81. 
These  are  valuable  where  large-sized  torch  tips  are  used 
more  or  less  continuously,  since  the  capacity  of  the  cylinders 
supplying  acetylene  should  be  at  least  seven  times  the  hourly 

116 


GAS-TORCH   WELDING   AND   CUTTING   OUTFITS 


117 


consumption.  Where  the  hourly  requirements  are  from  61 
to  75  cu.ft.  of  acetylene,  5-WC  or  2-AVK  size  cylinders  should 
be  used. 

Complete  Working  Outfits. — A  welding  or  cutting  outfit 
may  consist  of  the  bare  essentials,  or  be  so  complete  as  to 


OXYGEN  REGULATOR 


Oxygen  Tank  Valve ----;>[ 
Connection   Hut- 
Safety  Valve--" 

ACETYLENE  REGULATOR 

Tank  or  High. 

-Pressure  Gage 
Connecting  Nut' 

Adapter 
Safety  Valve  - 


Tank  or  High- 
Pressure  Gage 
:-  -Low  -Pressure 

Gage 
-Handle 

Ouilet  Connection 


^-Cutting 
Nozzle 

'--Torch 
Head 


TORCH 

Cutting  Valve* 
,  -Lever 


-Handle 

Oxygen 
"Valve 

.Oxygen  Hose 
Connection 


Acetylene  Hose-' 
FIG.  79 Typical  Oxy- Acetylene  Cutting  Unit. 

include  everything  that  will  be  needed  to  care  for  any  job 
that  will  come  along.  The  outfits  may  also  be  of  either  the 
stationary  or  the  portable  type,  or  a  combination  of  the  two. 
If  of  the  stationary  type,  there  will  naturally  be  included 
many  things  such  as  holding  jigs  and  fixtures  which  do  not 


118  GAS   TORCH   AND  THERMIT  WELDING 


PlG.  80. — Oxweld  Oxygen-Cylinder  Manifolds. 


PIG.  81. — Prest-O-Lite  Acetylene-Cylinder  Manifolds. 


GAS-TORCH  WELDING  AND  CUTTING  OUTFITS         119 

ordinarily  belong  to  the  strictly  portable  type.  Two  typical 
lists  of  parts  and  material  for  the  ordinary  run  of  work,  where 
gas  cylinders  are  used,  are  here  given.  These  lists  are  taken 
from  the  catalogue  of  the  K-G  Welding  and  Cutting  Co., 
New  York. 

OXY-ACETYLENE    CUTTING    UNIT 

1  cutting    torch,    standard    size,    with    four    interchangeable    tips    of 

graduated  sizes. 
1  high-pressure    oxygen    regulator,    with    3000-lb.    gage    for    cylinder 

pressure,  300-lb.  gage  for  working  pressure  and  one  reducing  valve 

with  connection  for  hose  coupling  and  needle  valve. 
1  acetylene-pressure  regulator  with  400-lb.  gage  for  cylinder  pressure, 

60-lb.   gage  for  working   pressure   and   one  reducing  valve  with 

connection  for  hose  coupling  and  needle  valve. 
25  ft.  high-pressure,   copper-covered  oxygen  hose. 
25  ft.  steel-covered  gas  hose. 
1  pair  colored  goggles  for  operator. 

1  pair  fireproof  gloves. 

2  wrenches  and  flint  lighter,  instructions,  etc. 
1  leather  instruction  and  memorandum  book. 

OXY-ACETYLENE  WELDING  UNIT 

1  welding  torch,  standard  size,  complete  with  eight  interchangeable 
tips  of  graduated  sizes. 

1  low-pressure  oxygen  regulator,  with  3000-lb.  gage  for  cylinder  pres- 
sure, 60-lb.  gage  for  working  pressure  and  one  reducing  valve 
with  connection  for  hose  coupling  and  needle  valve. 

1  acetylene-pressure  regulator  with  400-lb.  gage  for  cylinder  pressure, 
60-lb.  gage  for  working  pressure,   and  one  reducing  valve  with 
connection  for  hose  coupling  and  needle  valve. 
25  ft.  red  corrugated-rubber  oxygen  hose. 
25  ft.  black  corrugated-rubber  gas  hose. 

1  pair  colored  goggles  for  operator. 

1  pair  fireproof  gloves. 

2  wrenches,  1  flint  lighter,  instructions,  etc. 
10  Ib.  cast-iron  rods. 

10  Ib.  Norway  iron  for  welding. 
2  Ib.  aluminum  rods. 
1  Ib.  cast-iron   flux. 
\  Ib.  aluminum  flux. 

It,  of  course,  is  not  necessary  for  a  user  to  purchase  two 
complete  units  if  his  work  does  not  warrant  it,  as  these  may 
be  judiciously  combined.  For  instance,  the  welding  unit  may 
be  used  for  either  welding  or  cutting  if  a  cutting  torch  and 


120 


GAS  TORCH  AND   THERMIT  WELDING 


a  high-pressure  oxygen  regulator  are  added.  It  is  very  con- 
venient where  portable  apparatus  is  used  to  a  considerable 
extent  over  an  extended  territory,  to  have  a  suitable  carrying 
case  for  the  smaller  parts.  This  may  consist  of  a  chest  attached 
to  the  cylinder  or  portable  truck,  or  of  a  hand  case,  such  as 
shown  in  Fig.  82.  This  case  and  outfit  is  sold  by  the  Air 
Reduction  Sales  Co.,  New  York,  and  holds  everything  neces- 
sary for  immediate  attachment  to  the  cylinders  and  starting 
to  work. 

It  has  been  previously  mentioned  that  it  is  not  advisable 


FlG.  82. — Carrying  Case  for  Welding  and  Cutting  Outfit. 

to  place  gas  cylinders  so  that  they  may  be  knocked  over. 
If  they  have  to  be  stood  up  near  the  work,  it  is  best  to  chain 
them  to  a  post  or  brace  them  up  in  some  way.  A  portable 
truck  is,  of  course,  the  best  of  all  where  outfit  must  be  moved 
about.  Such  a  hand  truck  has  already  been  shown.  Prac- 
tically every  firm  making  gas-torch  supplies  sells  a  similar  one. 
A  very  important  part  of  any  gas-torch  outfit  is  a  pair 
of  suitable  glasses  or  goggles.  These  should  not  be  merely 
dark  glasses,  but  the  lens  should  be  made  expressly  for  work 
of  this  kind.  Cheap  glasses  are  dear  at  any  price,  as  the  result 
may  be  ruined  eyesight  from  the  intense  glare  of  the  hot  metal 


GAS-TORCH   WELDING  AND  CUTTING  OUTFITS         121 

or  from  injurious  rays.  The  glasses  may  be  of  either  the 
spectacle  or  the  goggle  form,  but  the  lens  should  be  the  same 
in  either  case.  Glasses  may  be  obtained  from  practically  any 
of  the  firms  mentioned  in  the  various  descriptions.  The  goggle 
form  of  glasses  has  the  advantage  over  those  of  the  spectacle 
type  in  that  they  will  better  protect  the  eyes  from  flying  or 
glancing  particles  of  hot  metal  or  sparks.  It  is  well  to  have 
the  colored  lens  protected  by  clear  glass.  A  pair  of  goggles 
is  shown  in  Fig.  83.  These  are  of  a  very  satisfactory  form. 
They  are  light  and  all  parts 'that  come  in  contact  with  the  skin 
should  be  made  of  fiber,  metal,  or  something  that  is  sanitary 
and  easily  sterilized.  The  guards  may  be  made  of  aluminum 
screen  or  fiber.  Never  on  any  account  use  goggles  with  guards 


FlG.  83. — Goggles  for  Gas-Torch  Work. 

made  of  celluloid.  If  the  glasses  used  can  be  employed  for 
long  periods  of  time  without  the  eyes  feeling  "dazzled,"  or 
if  they  can  be  removed  without  white  spots  appearing  before 
the  eyes,  then  they  are  all  right.  Otherwise  get  others  that 
are  better  fitted  for  the  work  and  your  eyes.  A  darker  lens 
is  usually  used  for  welding  than  for  cutting  and  sometimes  it 
is  advisable  to  use  different  glasses  for  different  metals.  These 
will  enable  the  operator  to  see  more  clearly  when  the  glare 
is  not  so  intense. 

Fire-fighters  often  need  to  cut  through  steel  or  iron  win- 
dow bars,  shutters,  steel  plates  or  sheathing,  in  order  to  rescue 
imprisoned  persons  or  to  get  at  a  fire  advantageously.  For 
this  purpose  the  Davis-Bournonville  Co.  supplies  a  very  com- 
pact apparatus,  shown  in  Fig.  84.  The  metal  case  is  6i  in, 


122  GAS  TORCH  AND  THERMIT  WELDING 

wide,  14  in.  deep  and  50  in.  high.  It  contains  a  40-cu.ft. 
cylinder  of  acetylene,  a  50-cu.ft.  cylinder  of  oxygen,  and  a 
complete  cutting  unit  with  extra  length  of  hose.  Handles  on 
each  side  of  the  case  provide  means  for  easy  carrying  by  two 


FIG.  84.— Emergency-Cutting  Outfit. 

men,  and  these  handles  placed  as  shown,  when  in  use,  insure 
stability.     The  complete  outfit  weighs  125  Ib. 

A  complete  two-station  welding  and  cutting  outfit  of  the 
stationary   type,   using   an   acetylene    generator   and   oxygen 


GAS-TORCH  WELDING  AND  CUTTING  OUTFITS         123 


T3 

§ 
I 


124 


GAS  TORCH  AND  THERMIT  WELDING 


cylinders,  is  shown  in  Fig.  85.  This  can  be  extended  to  include 
any  number  of  individual  stations,  according  to  the  size  of 
the  generator  employed.  It  is  advisable  to  place  the  acetylene 
generator  in  a  separate  room  or  building.  The  oxygen  cylinders 
and  regulators  are  placed  within  easy  reach  of  the  workers. 
Back-Pressure  Valves. — Hydraulic  back-pressure  valves 


PIG.  86.— Oxweld   Low-Pressure   Hydraulic   Back-Pressure   Valve. 

should  always  be  connected  to  the  individual  acetylene  pipes, 
as  shown,  to  avoid  the  danger  of  a  flashback  or  an  explosive 
mixture  entering  the  acetylene  line.  An  Oxweld  low-pressure 
back-pressure  valve  is  shown  in  Fig.  86.  In  some  quarters  it 
is  thought  that  such  a  valve  is  not  needed  where  positive- 
pressure  torches  are  used,  but  this  is  not  true,  as  the  danger 


GAS-TORCH  WELDING  AND  CUTTING  OUTFITS         125 

is  always  present  when  the  oxygen  pressure  is  greater  than 
that  of  the  acetylene  or  which,  through  accident,  may  become 
greater.  An  obstruction  in  the  nozzle  of  the  torch,  or  clogging 
of  certain  passages  is  apt  to  force  the  oxygen  into  the  acety- 
lene line.  There  are  also  other  conditions  which  may  cause 
a  serious  accident.  While  mechanical  valves  may  help,  they 
are  not  so  reliable  as  hydraulic  valves  and  should  not  be  used 
on  shop  lines.  In  the  valve  shown,  the  acetylene  enters  at  A  and 
bubbles  out  at  B  where  it  rises  to  the  surface  of  tfye  water 
seal,  and  normally  goes  out  of  the  hose  valve  C.  The  depth 
of  the  water  through  which  the  acetylene  bubbles  is  sufficient 
to  cover  the  tube  leading  to.  the  outside  air.  If  there  is  a 
backward  flow  of  oxygen,  the  pressure  exerted  on  the  surface 
of  the  water  lowers  its  level,  causing  it  to  rise  in  the  tube 
open  to  the  air,  and  if  continued,  forces  it  out  of  the  tube, 
thus  opening  a  clear  passage  for  the  oxygen  to  the  outside 
air  at  D.  The  acetylene  inlet  meanwhile  is  protected  by  a  seal 
of  water. 

To  avoid  the  possibility  of  blowing  the  water  out  of  the 
seal,  the  valve  is  so  designed  that  in  ease  of  a  blow-back  the 
water  automatically  flows  back  to  the  body  of  the  valve,  renewing 
the  seal. 

The  high-pressure  valve  of  this  type  is  provided  with  a  ball 
check  seated  under  water,  which  effectually  prevents  an  excess 
pressure  from  working  backward  into  the  generator.  It  is 
also  supplied  with  a  relief  valve  of  ample  size  to  carry  off 
any  excess  pressure  which  may  accumulate  in  the  body  of  the 
hydraulic  valve. 

Both  the  high-pressure  and  low-pressuro  valves  should  be 
kept  full  of  water  up  to  the  screw  plug  E  which  is  provided 
to  regulate  the  height  of  water  when  filling. 

Lead  Burning.— Lead  burning  is  practically  the  same  as  any 
other  welding  work,  except  that  the  melting  point  of  lead 
(620  deg.  F.)  calls  for  a  much  smaller  flame.  The  same  outfits 
intended  for  lead  burning  may  be  used  for  welding  jewelry, 
small  metal  parts  of  various  kinds,  or  for  brazing  work  in 
some  cases.  On  account  of  the  torch  itself  being  made  small 
and  as  light  as  possible,  it  is  customary  to  have  only  an  oxygen 
valve  on  it,  the  gas  and  oxygen  valves  being  placed  in  a  "  bench 
block"  placed  about  midway  between  the  torch  and  the  sources 


126 


GAS  TORCH  AND  THERMIT  WELDING 


of  supply.  For  lead  burning  alone,  it  is  usually  advisable  to 
use  some  gas  combination  giving  less  heat  than  oxy-acetylene, 
such  as  oxy-hydrogen,  hydrogen  and  compressed  air,  oxygen 


FIG.  87. — Oxy-Acetylene  Lead-Burning  Outfit. 


FIG.  88. — Oxy-Hydrogen  Lead-Burning  Outfit. 

and  illuminating  gas,  or  others.  In  order  to  assist  the  would-be 
user,  several  typical  set-ups,  taken  from  the  Imperial  Hand- 
book, will  be  shown. 

An  oxy-acetylene  combination  is  shown  in  Fig.  87.     This 


GAS-TORCH  WELDING  AND   CUTTING  OUTFITS         127 

shows  the  bench  block  A,  screwed  to  the  wall,  which  in  many 
cases  is  the  better  way.  However,  it  is  well  to  have  this  block 
in  easy  reach  of  the  operator.  The  oxy-hydrogen  set-up  is 
very  similar,  as  shown  in  Fig.  88. 

A  hydrogen  compressed-air  unit  is  shown  in  Fig.  89.  A 
constant  air-pressure  regulator  is  shown  attached  to  the  air 
line.  In  Fig.  90  is  shown  an  oxygen-illuminating  gas  combina- 
tion. A  water  seal  is  used  on  the  gas  line  as  a  safeguard  and 
to  act  as  a  scrubber  to  some  extent. 

A  very  light  outfit,  intended  for  jewelers,  dentists,  or  ex- 


FIG.  89. — Hydrogen  and  Compressed-Air  Outfit. 

perimental  laboratory  work,  is  shown  in  Fig.  91.  The  bench 
block  differs  some  from  the  ones  just  illustrated.  The  torch 
itself  is  almost  as  light  and  is  about  the  size  of  a  large  fountain 
pen.  With  the  bench  block  close  to  the  operator,  the  torch 
valve  is  not  needed.  This  outfit  is  made  by  the  Davis-Bournon- 
ville  Co.  A  very  convenient  feature  is  the  torch-holding  clip, 
shown  at  the  top  of  the  bench  block.  This  obviates  the  neces- 
sity of  laying  the  torch  down  at  any  time,  with  its  attendant 
danger  of  fire. 

A  Gas  Flow  Indicator. — It  is  often  desirable  to  measure 
the  flow  of  gases  used  in  a  welding  or  cutting  torch.  For  this 
purpose,  the  Hydrate  Engineering  Corporation,  Buffalo,  N.  Y., 


128 


GAS  TORCH  AND  THERMIT  WELDING 


has  produced  the  Hydrex  Flow  Indicator  shown  in  Fig.  92. 
In  Fig.  93  the  principle  on  which  it  works  is  outlined.  The 
gas  enters  the  nipple  a,  as  indicated  by  the  arrow.  Thence  it 
flows  into  the  chamber  c,  up  through  the  tube  d  and  out  the 
nipple  &.  As  the  gas  passes  into  tube  d  it  raises  the  plunger  e. 
The  greater  the  flow  of  gas  the  higher  will  the  plunger  be 
lifted.  The  disk  /  is  suspended  from  plunger  e  and  is  visible 
through  the  gas  tube  g,  so  that  the  flow  of  gas  is  indicated 
on  a  scale  calibrated  in  cubic  feet  per  hour,  reduced  to  normal 


FIG.  90. — Oxygen  and  Illuminating  Gas  Outfit. 

conditions   for   a   gas   flowing  at   a   definite   pressure    and,  a 
definite  temperature. 

The  gas  at  the  time  it  is  measured,  may  flow  at  a  known 
pressure  and  a  known  temperature,  which  do  not  coincide  with 
those  for  which  the  calibration  is  prepared.  In  such  a  case 
the  reading  has  to  be  converted  into  the  proper  volume,  by 
applying  those  formulas  which  govern  flow  of  gas  through 
orifices. 

•  These  calculations,  of  course,  should  not  be  necessary  for 
a  conveniently  applicable  apparatus.  The  elimination  of  com- 
putations is  accomplished  by  the  use  of  a  chart,  which  permits 


J  GAS-TORCH   WELDING  AND   CUTTING   OUTFITS         129 

the  conversion  of  a  reading  for  any  pressure  and  temperature. 
This  is  practical  in  the  laboratory  where  close  observation 
and  intelligent  interpretation  of  the  chart  may  be  expected. 
For  the  ordinary  shop  work  it  is  out  of  place. 

To  make  the  instrument  a  practical  and  convenient  shop 
and  an  all-around  test  apparatus,  it  was  necessary  to  simplify 
the  determination  of  the  volume  passing  through  the  flow  in- 


FIG.  91. — Manufacturing  Jewelers'  and  Dentists'  Welding  Outfit. 

dicator.  A  pressure  gage  makes  this  possible.  This  pressure 
gage  indicates  factors  instead  of  pressures  in  pounds  per  square 
inch.  The  reading  on  the  flow  indicator  scale,  multiplied  by 
the  factor,  is  the  actual  volume  of  gas,  reduced  to  normal 
conditions,  passing  through  the  flow  indicator.  Thus,  the  shop 
operator  is  relieved  of  all  complicated  mathematical  considera- 
tions and  he  may  concentrate  his  energies  upon  his  work. 


130 


GAS  TORCH  AND  THERMIT  WELDING 


The  influence  of  the  temperature  upon  the  reading  is  ap- 
proximately 1  per  cent  for  each  10  deg.  F. 

The  influence  of  the  pressure  upon  the  volume  is  inverse  to 
that  of  temperature,  increasing  temperature  decreases  the  den- 
sity of  gas,  while  increasing  pressure  will  increase  the  density. 


FIG.  92. 


IG.  93. — Details  of  Gas  Flow 
Indicators. 


On  a  calibration  made  for  40  lbs./in.2  gage  pressure,  the 
increase  of  one  pound  in  pressure  compensates  for  an  approxi- 
mate increase  of  10  deg.  in  temperature;  and  if  the  calibration 
is  for  10  lbs./in.2  gage  pressure,  an  increase  of  J  lb./in.2 
pressure  will  compensate  for  an  increase  of  approximately 
10  deg.  F. 


CHAPTER  IX 
LEARNING  TO  WELD  WITH  A  GAS  TORCH 

Directions  as  to  how  to  handle  a  gas  torch  and  to  weld 
are  of  no  use  without  actual  practice — and  lots  of  it.  How- 
ever, the  would-be  welder  should  have  certain  definite  instruc- 
tions given  him  before  he  attempts  to  do  any  work.  To  be- 
come a  first-class  all-round  welder  requires  long  experience,  a 
mechanical  sense,  and  a  liberal  application  of  brains  as  a  flux 
on  every  job.  Learning  to  do  simple,  one-operation  welding 
jobs,  however,  is  comparatively  easy  if  a  competent  instructor 
is  to  be  had.  If  such  an  instructor  is  not  to  be  had,  the  direc- 
tions given  here  will  serve  as  a  foundation  upon  which  a  fair 
knowledge  of  the  work  may  be  built.  It  is  easier  to  learn  to 
cut  than  it  is  to  learn  to  weld,  but  as  welding  is  the  more  im- 
portant of  the  two  the  method  will  be  described  first. 

It  is  taken  for  granted  that  the  welder,  following  directions 
already  given,  is  familiar  with  his  apparatus,  has  the  correct 
size  of  tip  for  the  metal  to  be  welded,  knows  how  to  light  his 
torch  and  has  ample  gas  for  the  work.  In  making  a  gas-torch 
weld,  it  is  necessary  that  fusion  penetrate  entirely  through 
the  metal.  In  order  to  aid  this  the  pieces  are  usually  cham- 
fered Or  beveled  with  an  air  hammer,  a  grinder,  or  cold  chisel. 
By  beveling  is  meant  the  grooving  or  chamfering  of  the  metal 
at  the  line  of  the  weld,  the  depth  of  this  groove  or  V  being 
equivalent  to  the  thickness  of  the  metal. 

Beveling  is  not  required  on  castings  or  plates  lighter  than  1/8 
in.  in  thickness.  From  1/s  in.  to  3/16  in.  in  thickness  a  chamfer 
of  45  deg.  on  each  piece,  or  a  total  angle  opening  of  90  deg., 
is  about  right.  From  3/16  in.  up  to  the  maximum  thickness 
weldable  by  the  gas  torch,  an  angle  opening  of  from  60  deg. 
to  90  deg.  is  used,  the  angle  being  dependent  somewhat  upon 
the  nature  of  the  material  and  the  location  of  the  weld.  On  very 
thick  metal  a  channel  with  parallel  sides,  beveled  only  at  the 
bottom,  is  frequently  used. 

131 


132 


GAS  TORCH  AND  THERMIT  WELDING 


Under  certain  conditions  it  is  advisable,  but  seldom 
economical,  to  use  an  oxygen  cutting  torch  for  beveling.  In 
case  this  is  done,  care  must  be  taken  that  all  the  oxide  pro- 
duced on  the  surfaces  cut  by  the  torch  is  removed  before 
welding.  The  beginner  should  start  by  welding  strips  of 
rolled  iron  or  steel  -J  in.  thick  and  about  1J  X  6  in.  These 
may  be  welded  without  the  use  of  a  welding  rod.  The  pieces 
must  be  properly  cleaned  and  free  from  scale,  grease  or  dirt. 
The  operator  must  wear  suitable  colored  goggles,  and  should 
grasp  the  handle  of  the  torch  firmly.  It  is  not  good  practice 
to  hold  it  in  tlio  fingors,  because  it  is  impossible  to  manipulate 


FIG.  94. — The  Way  to  Hold  the  Torch. 

the  flame  with  as  great  regularity  and  control,  nor  will  it  be 
possible  to  do  as  heavy  work  without  tiring. 

Occasionally,  the  hose  is  thrown  over  the  man's  shoulder. 
In  this  case  the  weight  of  the  torch  is  suspended  and  held  by 
the  tubing,  so  that  it  is  only  necessary  to  impart  the  typical 
welding  motion  to  the  torch,  which  can  usually  be  done  by 
the  fingers.  The  movement  of  the  welding  flame  is  hindered, 
however,  and  this  method  is  therefore  not  recommended.  It 
should  be  used  only  as  a  relief  when  the  work  is  of  long  dura- 
tion and  the  operator's  wrist  and  forearm  become  tired. 

The  head  of  the  torch  should  be  inclined  at  an  angle  of 
about  60  deg.  to  the  plane  of  the  weld,  as  in  Fig.  94.  The 


LEARNING   TO  WELD  WITH  A  GAS  TORCH 


133 


inclination  of  the  head  should  not  be  too  great,  because  if  it  is 
the  molten  metal  will  be  blown  ahead  of  the  welding  zone  and 
will  adhere  to  the  comparatively  cold  sides  of  the  weld.  On 
the  other  hand,  the  welding  head  should  not  be  inclined  too 
near  the  vertical,  because  in  that  case  the  preheating  effect 
of  the  secondary  flame  will  not  be  efficiently  applied. 

There  are  certain  cases,  however,  where  the  conductivity 
of  the  metal  is  such  that  it  is  not  necessary  to  utilize  this  pre- 
heating. Also  certain  metals  have  the  property  of  absorbing 
the  gases  of  the  flame.  Consequently,  in  these  cases  it  is  best 
that  the  flame  impingement  be  concentrated  to  as  small  an  area 
as  possible. 

Torch  Motion. — The  motion  of  the  torch  should  be  away 


FIG.  95. — Different  Flame  Movements. 

from  the  welder  and  not  toward  him,  as  closer  observation  of 
the  work  can  be  obtained  and  greater  facility  in  making  the 
weld  will  be  experienced. 

Where  very  thin  sheet  material  is  being  welded  and  it  is 
not  necessary  to  use  a  welding  rod  or  wire,  a  weld  may  be 
produced  by  moving  the  torch  in  a  straight  line.  It  can 
readily  be  seen  that  this  does  not  apply  to  welds  which  have 
been  beveled,  and  which  require  the  use  of  filling  material, 
for  in  this  case  a  swinging  motion  must  be  imparted  to  the 
torch  to  take  in  both  edges  of  the  weld  and  the  welding  wire 
at  practically  the  same  time. 

In  comparatively  light  work  a  motion  is  imparted  to  the 
torch  which  will  cause  the  incandescent  cone  to  describe  a 
series  of  overlapping  circles,  the  overlapping  extending  in  the 


134  GAS  TORCH  AND  THERMIT  WELDING 

direction  of  the  welding,  as  shown  at  A,  Fig.  95.  In  order 
that  the  weld  be  of  a  good  appearance  this  must  be  constant 
and  regular  in  its  advance.  .The  width  of  this  motion  is  de- 
pendent upon  the  size  of  the  material  being  welded  and  varies 
according  to  the  nature  of  the  work.  In  some  cases  a  move- 
ment like  a  figure  8  is  used,  as  shown  at  B,  but  this  is  a  rather 
complicated  one  for  a  beginner.  In  heavier  work,  if  the  system 
described  were  used,  a  great  deal  of  the  motion  would  be 
superfluous.  Consequently,  either  an  oscillating  movement,  or 
one  in  which  the  jet  of  the  torch  will  describe  semi-circular 
zig-zags,  as  at  C,  should  be  used.  This  confines  the  welding 
zone  ;  and  while  the  progress  is  not  so  fast,  it  is  more  thorough 
than  the  other  system  for  this  class  of  work. 

To  the  average  beginner  the  regular  control  of  these  mo- 
tions is  difficult,  and  considerable  practice  is  required  to  be- 
come skilled.  It  is  the  regularity  of  these  motions  that  pro- 


Wfefl/  Finished 

Here  X^  Weld    \ 


k-/..>K"/.*i      H-~  ...........  6"  -  ..........  -—  H 

FIG.  96.  —  Plates  and  Finished  Butt  Weld. 

duces  the  characteristic  even-rippled  surface  of  good  gas-torch 
welding.  The  progress  of  a  welder  and  the  quality  of  his 
work  can  be  determined  to  some  extent  by  the  skill  with  which 
he  produces  this  effect. 

On  the  practice  pieces  of  %-m.  thick  material,  the  operator 
should  so  manipulate  the  jet  as  to  take  in  about  J  in.  on  each 
side  of  the  joint.  The  point  of  the  cone  of  the  flame  should 
be  held  about  1/16  in.  from  the  metal,  but  not  actually  touching 
it.  On  thicker  metal  the  distance  of  the  cone  tip  will  need  to 
be  greater,  or  about  £  in.,  depending  on  'the  size  of  the  tip 
used.  It  is  far  better  to  have  the  torch  too  far  away  than 
too  close,  as  a  hole  may  be  blown  through  the  metal.  Start 
to  weld  at  the  end  of  the  joint,  and  as  the  metal  commences 
to  get  red  give  the  torch  a  swinging  motion  from  side  to 
side.  Keep  this  up  until  the  corners  of  the  plates  are  run 
together  clear  through  their  thickness.  Then  go  on  until  the 
entire  length  is  welded.  Do  not  move  the  torch  any  faster 
than  necessary  to  give  the  metal  a  chance  to  run  together 


LEARNING  TO  WELD  WITH  A  GAS  TORCH  135 

properly.  Be  sure  that  the  bottom  edges  of  the  plates  are 
melted  together  before  going  ahead  farther.  The  plates  and 
the  way  finished  weld  looks  are  shown  in  Fig.  96. 

Care  should  be  taken  not  to  touch  the  torch  tip  to  the 
metal,  as  this  will  obstruct  the  flow  of  gas  and  may  cause 
it  to  backfire  and  burn  inside  the  tip.  In  such  a  case,  shut  off 
the  oxygen  at  once,  then  the  gas,  and  cool  the  tip  in  cold 
water.  Then  relight  according  to  previous  instructions. 

Do  not  go  back  over  the  weld  unless  absolutely  necessary. 
Do  not  run  the  hot  metal  on  top  of  the  cold  metal.  Do  not 
leave  blowholes,  scale  nor  low  spots  in  your  weld.  A  blowhole 
is  a  bubble  in  the  metal.  It  sometimes  occurs  alone,  and  other 
times  there  are  several  of  them.  It  maks  the  metal  look  spongy 


ABC 

FIG.  97. — Plates  Welded  Without  Proper  Divergence. 

or  porous  and  is  caused  by  not  properly  running  the  metal 
together  or  by  leaving  impurities  in  the  weld. 

When  metal  is  melted,  a  coating  which  flakes  off  is  formed. 
This  coating  is  called  scale  and  is  bluish  steel-gray  in  color. 

Low  spots  are  unfilled  spaces  in  the  metal  caused  by  moving 
the  torch  too  fast  or  unevenly. 

The  beginner  will  soon  discover  that  two  pieces  laid  with 
the  edges  close  together  will  not  weld  properly,  as  they  will 
at  first  diverge,  as  shown  at  A,  Fig.  97.  Then  they  will 
gradually  draw  together  as  at  B  when  the  weld  is  about  half 
done.  From  this  point  on  the  edges  will  draw  in  until  they 
overlap  about  as  shown  at  C.  There  are  two  methods  of 
overcoming  this:  The  first  is  to  "tack"  the  two  strips  at 
intervals,  as  shown  at  A,  Fig.  98.  This  method,  however,  has 
the  disadvantage  of  causing  buckling  or  warping  under  certain 
conditions.  This  warping  may  in  some  cases  be  eliminated  by 


136 


GAS  TORCH  AND  THERMIT  WELDING 


rolling  or  hammering  after  welding.  The  second,  and  more 
satisfactory  method,  is  to  diverge  the  plates,  as  shown  at  B. 
The  amount  of  divergence  is  dependent  to  some  extent  upon 
the  thickness  and  nature  of  the  metal,  but  it  is  safe  to  say 
that  this  divergence  should  not  be  less  than  2^  per  cent,  nor 
more  than  6  per  cent  of  the  length  of  the  weld.  Some  operators 
stick  to  the  hard  and  fast  rule  of  J  in.  per  foot,  which  is  a 
very  satisfactory  figure  in  general.  However,  to  obtain  the 
best  results  it  is  sometimes  best  to  deviate  from  this,  as  prac- 
tice and  experience  dictate.  In  welding  a  sheet-metal  cylinder, 
it  is  often  necessary  to  insert  a  wedge  or  pin,  as  shown  at  C, 


FlG.  98. — Methods  of  Allowing  for  Seam  Contraction. 

in  order  to  obtain  the  proper  separation  and  prevent  over- 
lapping. 

On  very  thin  sheets,  it  is  usually  advisable  to  flange  the 
edges,  instead  of  trying  to  butt  weld  with  or  without  adding 
material  from  a  welding  rod.  The  flanges  are  turned  as  shown 
at  D.  The  flanges  may  be  tacked  as  for  butt  welding,  or 
clamped  with  tongs,  as  shown.  In  regular  manufacturing  work, 
where  the  welding  proceeds  rapidly,  it  is  common  to  have  a 
helper  move  the  tongs  ahead  of  the  welder.  Any  warping 
can,  as  a  rule,  be  easily  ironed  out  of  the  thin  sheets.  In  some 
cases,  the  edges  are  lapped  and  both  edges  welded,  either  using 
a  welding  rod  or  not,  according  to  the  nature  and  uses  of  the 
parts  being  welded. 

It  is  very  important  that  the  beginner  should  test  his  work 


LEARNING  TO   WELD   WITH  A  GAS  TORCH  137 

by  bending  the  metal  sharply  at  the  weld  and  carefully  in- 
specting for  defects,  which  should  be  overcome  on  the  next 
piece.  The  tendency  of  a  beginner  is  to  experiment  on  all 
sorts  and  thicknesses  of  metal,  but  he  will  progress  faster  if 
he  sticks  to  one  kind  and  thickness  until  he  masters  it.  The 
beginner,  as  well  as  the  more  experienced  welder,  should  occa- 
sionally test  his  flame  to  be  sure  he  is  maintaining  the  proper 
neutral  flame.  This  is  done  by  turning  off  the  oxygen  until 
a  shadowy  point  appears  on  the  cone.  The  oxygen  is  then 
turned  on  again  until  this  shadowy  point  just  disappears  into 
the  cone.  The  reason  for  this  testing  of  the  flame,  is  that 
changes  in  temperature  of  the  torch  or  variations  in  pressure 
may  alter  the  flame  without  the  operator's  knowledge,  and 
thus  injure  the  weld  by  either  carbonizing  or  oxidizing  the 
metal,  according  to  whether  there  is  an  excess  of  acetylene 


FIG.  99. — Beveled-Edge  Plates  and  Flame  Movement. 

or  of  oxygen.  If  the  tip  should  become  clogged  from  any 
cause,  it  should  be  cleaned  out  with  a  soft  wire  or  a  piece  of 
wood,  taking  care  not  to  get  the  hole  in  the  tip  out  of  round. 

Using  the  Welding  Rod. — In  starting  to  use  the  welding 
or  filling  rod,  it  is  just  as  well  to  begin  to  weld  pieces  similar 
in  size  to  those  used  for  the  first  lessons  in  welding,  except 
that  the  pieces  should  be  about  J  in.  thick,  and  beveled  on 
one  side  of  the  edges  only.  The  amount  of  divergence  is 
judged  as  in  the  case  of  the  plain  butt-welding  work,  as  shown 
at  A,  Fig.  99.  The  flame  movement  is  indicated  at  B. 

The  welding  rod  should  be  held  and  inclined  as  shown  in 
Fig.  100.  In  this  position  sufficient  quantity  of  metal  may 
be  added  at  the  right  time.  With  the  welding  "rod  held  in  a 
vertical  position  or  horizontal,  the  possibility  of  the  addition 
of  an  excess  of  metal,  part  of  which  is  not  fused,  is  great.  In 
adding  this  metal,  care  must  be  exercised  that  the  edges  of 


138  GAS  TORCH  AND  THERMIT  WELDING 

the  weld  are  in  the  proper  state  of  fusion  to  receive  it.  If  the 
metal  is  not  sufficiently  hot,  the  added  material  will  merely 
stick  to  the  sides  and  fusion  will  not  exist.  It  is  therefore 
necessary  that,  by  the  motion  of  the  torch,  fusion  be  produced 
at  the  edges  of  the  weld  equal  with  that  of  the  welding  rod. 
The  usual  faults  of  the  beginner  are  failure  to  introduce 
the  welding  rod  at  the  proper  time  into  the  welding  zone, 
to  hold  the  rod  at  the  wrong  angle,  or  to  fuse  either  too  little 
or  too  much  of  the  rod.  The  filling  material  when  melted 
should  never  be  allowed  to  fall  into  the  weld  in  drops  or 
globules.  When  the  proper  time  arrives  to  add  it,  the  welding 


FIG.  100. — Using  a  Filling  Rod  in  Welding. 

rod  is  lowered  into  the  weld  until  it  is  in  contact  with  the 
molten  metal  of  the  edges.  When  in  this  position  the  flame 
of  the  torch  is  directed  around  it,  and  thus  fusion  is  produced. 

It  is  customary  to  add  metal  in  excess  of  that  of  the  original 
section,  and  round  it  over  nicely. 

There  are  several  very  important  reasons  for  doing  this. 
First,  the  weld  is  reinforced  and  the  strength  is  accordingly 
increased.  Second,  in  case  a  finished  surface  is  desired  a 
sufficient  stock  must  remain  to  allow  for  finish.  Third,  small 
pinholes  or  blowholes  may  be  found  just  under  the  surface 
of  the  weld,  which  do  not  extend  to  any  depth,  and  may  be 
removed  by  filing  or  machining. 


LEARNING  TO  WELD  WITH  A  GAS  TORCH 


139 


In  some  cases  the  plates  do  not  start  to  draw  together  until 
the  weld  has  nearly  reached  the  center.  In  a  case  of  this  kind 
it  is  good  policy  to  slow  down  the  welding.  After  the  weld 
has  been  completed  to  the  center,  the  plates  will  commence 
to  draw  together  more  rapidly,  and  in  case  the  plates  draw 


Bevel  on  metal  less 
than  |  or  \  in.  and  over 
6  in.  thick 


Beveling  of  sections 
over| in.  Thick  where 
parts  must  be  welded 
from  one  side  only 


Sections  over  |  in.  thick 
Parts  are  beveled  and 
welded  on  both  sides 


Shaft  beveled  to 
chisel  edge  for 
welding 


Proper  'method  of 
beveling  shaft  over 
1  in.  in  diam.eter 


ssswi. 

welding  different  ' 
thicknesses 


Weld  concave  head  Flat  end  to  be  Fla"9e  tobe  Welded 

in  steel  cylinder  welded  into  tube 


Pipe  butt  weld 


Lap  weld 


Edge  weld. 

To  have  a  depth  equal 
to  thickness  of  metal 


Corner  weld. 
First  side  to 
show  through 


Angle  corner  weld. 
Large  angle  first 
to  show  through 
before  finishing 


FIG.  101. — Various  Examples  of  Welding  Jobs. 

too  fast,  speed  up  on  the  welding  until  the  proper  distance 
is  secured  between  the  two  plates. 

After  the  beginner  has  practiced  until  he  can  make  a  good 
weld  on  the  plain  and  beveled  plates,  as  suggested,  he  may 
practice  on  the  forms  shown  in  Fig.  101.  These  forms  repre- 
sent most  of  the  kinds  he  will  encounter  in  the  regular  run 
of  work  in  a  job  or  general  repair  shop. 


140  GAS  TORCH  AND    THERMIT  WELDING 

Sources  of  Trouble. — It  will  be  well  to  repeat  to  some 
extent,  the  instructions  and  advice  previously  given,  in  order 
to  emphasize  the  danger  points : 

The  first  source  of  trouble  in  making  a  weld  is  improper 
adjustment  of  the  welding  flame.  If  the  flame  is  not  adjusted 
properly  the  resultant  weld  will  be  inferior.  The  commonest 
fault  is  the  presence  of  too  much  oxygen.  In  this  case,  unless 
the  welder  takes  a  great  deal  of  care  in  removing  the  oxide 
by  mechanical  means,  it  will  be  incorporated  throughout  the 
weld.  The  presence  of  oxide  prevents  the  thorough  blending 
of  the  metal,  and  therefore  decreases  its  strength. 

Failure  to  penetrate  to  the  bottom  of  the  weld  is  the  cause 
of  a  great  many  defects.  This  fault  is  not  only  that  of  a 
beginner,  but  also  that  of  the  more  skilled  operator.  Very 
often  the  desire  to  complete  a  weld  rapidly  will  cause  the 
operator  to  hasten  over  the  most  important  part  of  his  work, 
which  is  to  secure  the  absolute  fusion  of  the  edges  at  the 
bottom  of  the  weld,  before  filling  rod  is  added.  This  defect 
not  only  reduces  the  section  of  the  weld,  but  also  produces 
a  line  of  weakness  in  case  the  weld  is  submitted  to  bending 
or  transverse  strains. 

When  molten  metal  is  added  to  metal  which  is  not  in 
fusion,  a  weld  is  not  secured.  The  molten  metal  merely  sticks 
to  the  cooler  metal;  this  defect  is  common  with  careless 
operators.  It  may  be  caused  by  improperly  beveling  the 
pieces  to  be  welded,  by  the  faulty  manipulation  of  the  torch 
or  by  improper  use  of  the  welding  rod. 

For  the  beginner  it  is  at  first  difficult  to  distinguish  the 
proper  temperature  at  which  to  add  the  filling  material. 
Usually  he  applies  the  filling  rod  before  the  edges  of  the  weld 
are  in  fusion.  The  adhesion  in  this  case  occurs  at  both  edges. 
Occasionally,  one  edge  of  the  weld  is  in  fusion,  but  the  other 
is  not,  in  which  event  the  adhesion  is  restricted  to  one  side. 

In  some  cases  the  edges  of  the  weld  are  both  at  a  point 
of  fusion  too  soon.  Under  these  conditions  a  film  of  oxide 
may  exist  on  each  edge.  When  a  filling  material  is  added, 
adhesion  is  produced  with  a  film  of  oxide  separating  the  edges 
and  the  added  material.  Quite  often  an  operator,  in  applying 
the  welding  rod  to  the  weld,  will  concentrate  his  flame  on 
the  welding  rod  and  the  edges  of  the  weld.  As  he  plays  the 


LEARNING  TO   WELD   WITH  A   GAS   TORCH 


141 


torch  around  the  rod  he  will  inadvertently  force  some  of  the 
molten  metal  ahead.  The  metal  not  being  in  the  proper  state 
of  fusion,  there  will  consequently  be  only  a  small  area  of 
adhesion. 

In  welding  cast  iron,  copper,  and  to  some  extent  steel,  a 
very  common,  fault  of  the  beginner  is  that  of  forming  blow- 
holes or  porous  sections  in  the  weld.  This  can  be  overcome 
by  close  observation  of  the  work  while  welding  and  by  certain 
corrective  means,  the  principal  one  of  which  is  the  use  of 
proper  fluxes  and  proper  manipulation  of  the  welding  rod. 


,•  Weld  Here 


SLOT  ION  THROUGH  CLNTE.R  OF  BLVEL 


I  -  Melt  bottom  of  V 
7- Add  filling  rod  till  V  is  half  filled 
3- Add  filling  rod  till  Vis  filled 
4-  Melt  down  edge  of  metal  previously 
added  and  melt  bottom  of  Y 


5-  Add  filling  rod  till  V  is  half  filled 

6-  Add  filling  rod  till  V  is  filled 
7  -  Proceed   as  in  4 

Proceed  in  this  manner  till  weld  is 
completed 


FIG.  102. — Method  of  * '  Building  Up  "  a  Weld. 

It  is  needless  to  say  that  the  existence  of  such  defects  in  a 
weld  seriously  affect  its  ultimate  strength. 

Occasionally,  welds  are  encountered  in  which  dirt  or  some 
foreign  material  is  incorporated.  This  will  cause  porosity 
and  an  inferior  weld,  which  could  readily  have  been  avoided 
by  removing  the  material  either  before  or  during  the  execution 
of  the  weld. 

Built-Up  Welds. — Where  steel  of  considerable  thickness  is 
to  be  welded,  the  Oxweld  company  recommends  the  method  illus- 
trated in  Fig.  102.  In  the  example  selected  the  steel  plates 
are  f  in.  thick,  beveled  45  deg.  on  each  edge,  making  an  in- 
cluded angle  of  90  deg.  In  doing  the  work  in  this  way,  first 
melt  the  edges  of  the  bottom  of  the  V  together  for  a  length 
cf  1  in.  Add  the  welding  rod  to  this  length  until  the  V  is 
about  half  filled.  Be  sure  that  the  sides  of  the  V  are  melted 


142 


GAS  TORCH  AND  THERMIT  WELDING 


when  the  rod  is  added.  Then  go  back  over  this  and  fill  up 
the  V  3/32  in-  thicker  than  the  original  plate.  When  this  length 
of  weld  is  done,  melt  the  edges  of  the  plates  ahead  down  into 
the  bottom  of  the  V,  and  at  the  same  time  being  sure  that  the 
end  of  the  weld  already  finished  is  melted  and  flows  into  the 
botton  of  the  V.  Then  add  to  this  next  section  metal  until 
a  reinforcement  of  3/32  in-  greater  than  the  thickness  of  the 
plate  is  formed.  Keep  on  in  this  way  until  the  plates  are 
welded.  Near  the  finish  of  the  weld  it  is  necessary  that  the 
rod  be  given  a  slight  swinging  motion,  similar  to  the  torch. 
This  is  in  order  that  the  top  of •  the  V  be  entirely  covered. 

Vertical  Welds.— Where  plates  are  to  be  welded  with  the 
seam  in  a  vertical  position,  the  same  rule  for  the  amount  of 
divergence  is  used  as  for  those  in  any  other  position.  The 
weld  should  be  started  at  the  bottom  and  carried  upward  with- 


o 

o 

O 

K— -          -  /?' -•>! 

FIG.  103.— The  Way  to  Fill  Up  Holes. 

out  stopping  until  the  weld  is  completed.  Practice  on  work 
of  this  kind  will  give  the  welder  experience  in  the  control 
of  the  molten  metal  as  no  other  kind  of  weld  will,  and  he 
should  put  in  considerable  time  on  this  work. 

Filling  Up  a  Hole. — A  thing  that  every  welder  should  learn 
as  soon  as  he  has  mastered  the  simpler  welds,  is  to  fill  up  holes 
properly.  A  good  way  to  learn  is  to  take  a  piece  of  |-in. 
plate  and  drill  three  holes  in  it,  \,  \  and  \\  in.  in  diameter, 
as  shown  in  Fig.  103.  The  beginner  should  commence  with 
the  smaller  hole  first.  The  weld  should  be  started  by  melting 
down  the  top  edge  of  the  hole  in  one  place.  This  will  give 
a  slight  angle  to  one  side.  On  the  face  of  this  angle  metal 
is  added.  The  hole  is  built  up  by  adding  metal  continuously 
from  the  bottom  to  the  top  until  it  gradually  closes  up.  The 
welding  should  be  carried  on  around  the  hole,  however,  and 
should  not  be  built  up  from  one  side  only.  When  the  hole 


LEARNING  TO  WELD  WITH  A   GAS  TORCH  143 

is  properly  filled  in,  the  metal  should  meet  at  the  center. 
Proceed  with  the  }-in.  hole  and  the  IJ-in.  hole  exactly  in  the 
same  manner.  Turn  the  plate  over  and  clean  up  the  bottom 
side  by  melting  the  excess  metal  with  the  torch. 

Forming  Bosses  or  "Putting  On"  Metal. — The  forming  of 
bosses,  building  up  missing  parts,  or  putting  on  metal  where 
needed,  forms  a  very  important  part  of  a  welder's  work.  Con- 

t&r*** 

%i 


^ 


|< «•- =21  ' 

FIG.  104. — Building  Up  Bosses. 

sequently,  the  beginner  should  practice  work  of  this  kind 
as  soon  as  he  has  mastered  the  ordinary  run  of  welds  outlined. 
He  can  begin  by  building  up  bosses  an  inch  or  so  in  diameter 
and  1  in.  high  on  a  steel  plate,  keeping  at  the  work  until 
he  can  produce  a  boss  of  fairly  regular  outline.  He  can  then 
practice  on  square  or  rectangular  bosses.  Built-up  bosses  of 
this  kind  are  shown  in  Fig.  104.  Since  the  welder  has  already 
practiced  vertical  welds  he  should  have  little  trouble  in  placing 

•finished  We/d 
. .,  .,_      ^^^         mm^f^ 

•  T 

JL 

[^ _._   /2» ^ 

FIG.  105. — Putting  a  Collar  on  a  Shaft. 

his  metal  where  it  is  wanted.  Care,  however,  should  always 
be  taken  to  make  sure  that  there  is  perfect  fusion  of  the 
added  metal  and  the  plate  before  building  up  the  boss.  If 
a  good  weld  to  the  surface  of  the  plate  is  not  made,  the  rest 
of  the  work  is  worthless.  Be  sure  that  all  scale  and  dirt  are 
worked  out  of  the  metal. 

Another  type  of  built-up  weld  is  shown  in  Fig.  105.  In 
making  a  weld  of  this  kind  for  the  first  time,  take  a  piece 
of  2-in.  shaft,  12  in.  long  and  clean  off  the  surface  for  about 
3  in.  at  one  end.  Use  a  Vie-in-  welding  rod,  and  a  No.  10 


144  GAS  TORCH  AND   THERMIT  WELDING 

Oxweld  tip,  or  its  equivalent,  and  21-lb.  oxygen  pressure. 
Place  the  flame  of  the  torch  on  one  spot  of  the  surface  until 
it  is  melted.  Then  add  the  welding  rod.  Add  a  layer  of  1  in. 
wide  and  3  in.  long  along  the  shaft.  Make  this  layer  J  in. 
thick.  When  this  strip  is  finished,  weld  another  strip  on  top 
of  it,  starting  at  the  end  just  finished.  This  gives  a  strip 
of  added  metal  1  in.  wide,  3  in.  long  and  -J  in.  thick.  When 
this  is  done,  start  another  strip  at  the  side  of  this,  being 
careful  that  the  metal  of  the  shaft  is  melting  before  the  welding 
rod  is  added  and  also  that  the  edges  of  the  first  two  layers 
are  at  the  same  time  melted  down  to  the  shaft.  Proceed  with 
the  welding  exactly  the  same  as  just  described,  adding  strip 

-Weld  Here-.  .-Finished Weld ': 


FIG.  106. — Building  Up  Gear  Teeth. 

after  strip,  side  by  side,  until  the  end  of  the  shaft  is  covered 
all  around.  Remember  that  the  shaft  must  be  melted  before 
any  metal  can  be  added,  that  each  layer  must  be  melting  before 
another  layer  can  be  added  to  it,  and  that  each  strip  must 
be  welded  both  to  the  shaft  and  the  strip  next  to  it.  When 
the  shaft  is  completely  covered,  the  end  of  the  weld  should 
be  gone  over  with  the  welding  flame,  in  order  to  clean  it  up  and 
to  be  sure  that  a  weld  is  produced  at  this  point. 

Following  the  building-up  work  just  outlined,  it  is  a  good 
thing  to  practice  building  up  worn-  or  broken-out  teeth  in 
old  or  scrap  steel  gears,  as  shown  in  Fig.  106.  Before  a 
welder  attempts  to  do  any  actual  repair  work  on  gears,  how- 
ever, he  should  first  learn  more  about  expansion  and  contrac- 
tion, and  the  methods  of  overcoming  their  effects. 

WELDING    BACKWARD 

In  an  article  published  in  the  "Acetylene  and  Welding 
Journal,"  London,  England,  Capt.  D.  Richardson  describes 
a  method  of  welding  which  differs  considerably  from  the  gen- 
erally accepted  American  practice. 


LEARNING  TO   WELD   WITH  A  GAS  TORCH  145 

In  1916,  M.  Roulleau,  a  French  acetylene  engineer,  was  sent  by  his 
firm  to  Italy  in  connection  with  the  manufacture  of  large  welded  pro- 
jectiles. The  welds  were  being  made  by  welders  with  little  knowledge 
of  the  process  and  examination  showed  that  from  the  number  of  de- 
fective welds  obtained  it  would  be  difficult  to  get  worse  results.  The 
welds  were  porous,  adhesion  was  common,  and  the  solidity  of  the 
joints  was  extremely  bad.  The  supervision  of  the  1000  to  1200  welders 
distributed  through  seven  or  eight  different  works  was  a  serious 
problem.  The  daily  consumption  of  oxygen  and  carbide,  at  a  cost 
of  thousands  of  francs,  in  producing  work  of  the  type  described  made 
it  an  urgent  economic  problem  to  bring  about  improvement.  Faced 
with  these  various  problems,  M.  Roulleau,  after  experiment,  introduced 
the  method  of  welding  backward  into  the  various  Italian  workshops 
which  came  under  his  technical  supervision.  This  change  in  method 
produced  excellent  results  and  on  returning  to  France  after  a  mission 
of  three  years  in  Italy,  M.  Roulleau  collaborated  with  the  Union  de 
la  Soudure  AutogSne  with  a  view  to  a  wider  application  of  his 
method. 

Welding  backward  may  be  defined  as  the  method  of  executing 
a  weld  in  which  the  welding  rod  follows  the  torch  as  opposed  to 
preceding  it.  Or  again,  it  may  be  defined  as  a  method  in  which  the 
flame  is  inclined  towards  the  welded  portion.  A  fuller  and  perhaps 
better  definition  would  be :  The  flame  is  inclined  backwards  and  only 
undergoes  a  slight  transversal  motion  in  addition  to  its  regular  ad- 
vancement, the  welding  rod  follows  the  flame  and  is  given  a  movement, 
the  end  of  the  rod  always  being  molten. 

It  is  claimed  that,  having  acquired  the  method  of  welding  backward, 
the  welder  will  find  it  easier  to  execute  welds  and  that  the  penetra- 
tion is  always  satisfactory;  adhesion  is  almost  impossible;  the  metal 
is  sound;  there  is  a  diminution  in  the  amount  of  oxide,  and  the  metal 
is  more  ductile.  Finally,  that  the  speed  of  welding  is  greater  than 
with  the  old  method  from  which  it  will  be  gathered  that  there  is 
economy  in  labor  and  gases.  The  economy  in  the  consumption  of  filling 
material  is  of  the  same  order  as  it  is  possible  to  reduce  the  beveling 
angle. 

APPLICATIONS   OF  METHOD 

This  method  of  welding  is  applied  mainly  to  steel  plate  above  ylc 
in.  in  thickness.  It  should  be  used  on  all  plates  falling  in  the  range 
of  J  to  I  in.  in  thickness. 

The  process  is  particularly  valuable  for  certain  industries  such  as 
the  manufacture  of  boilers,  etc. 

Its  application  to  mild  steel  has  been  specially  studied.  A  number 
of  experiments  have  shown  that  welding  backward  gives  better  results 
than  the  usual  method  when  welding  steels  with  a  higher  carbon  con- 
tent— medium  and  hard.  It  is  not  satisfactory  for  aluminum  welding 
and  gives  indifferent  results  when  welding  cast  iron.  On  the  other 


146  GAS  TORCH  AND  THERMIT  WELDING 

hand,  the  first  series  of  tests  in  using  the  method  when  welding  copper 
and  brass  have  proved  satisfactory. 

When  comparing  this  method  of  executing  welds  with  other  methods, 
one  might  say  that  welding  backward  is  a  "more  mechanical"  method. 
From  this  it  follows  that  more  definite  rules  have  to  be  observed  in 
executing  welds  and  it  is  advisable,  especially  for  beginners,  to  strictly 
observe  the  rules  laid  down.  These  instructions,  which  are  the  result 
of  investigation,  may  subsequently  be  modified  and  added  to,  but  in 
the  meantime  they  give  good  results  and  should  be  followed. 

For  example,  it  will  be  noticed  that  for  this  method  of  welding, 
the  edges  of  the  two  pieces  of  metal  to  be  welded  should  be  chamfered 
or  beveled,  so  that  when  they  are  placed  together,  the  two  beveled 
edges  form  a  V.  Although  the  angles  of  the  bevel  can  be  reduced, 
beveling  is  still  indispensable,  even  on  thin  material. 

PREPARATION    OF   MATERIAL 

The  parts  to  be  welded  are  prepared  in  the  ordinary  way,  tacks, 
or  short  welds,  at  intervals  of  from  2  to  6  in.,  according  to  the 
thickness  of  material  may  be  used.  In  the  absence  of  jigs,  the  parts 
are  supported  so  that  the  lower  edges  are  in  the  same  horizontal  plane. 
The  angle  of  the  V  formed  by  the  two  beveled  plates  should  never 
exceed  90  deg.,  and,  as  already  mentioned,  for  this  method  can 
be  distinctly  less.  Beginners  can  gradually  reduce  the  angle  of  the 
V  from  the  previous  standard  of  90  deg.  until  they  arrive  at  60  deg. 
for  material  £  in.  in  thickness  or  above,  and  for  material  between  J 
in.  and  i  in.  an  angle  of  between  45  and  50  deg.  can  be  used. 

The  beveling  should  be  carefully  done  and  extend  the  full  depth  of 
the  plates  as  partial  beveling  will  produce  defective  welds. 

The  power  of  a  torch,  in  other  words,  the  quantity  of  heat  which 
it  is  capable  of  giving  out  in  a  given  time,  is  generally  measured  by  the 
number  of  cubic  feet  of  acetylene  burnt  in  an  hour  with  the  flame 
perfectly  regulated.  The  rule  which  has  been  adopted  for  welding 
steel  by  the  usual  method  of  executing  welds  can  be  followed,  namely, 
that  the  consumption  should  be  about  5  cu.ft.  of  acetylene  per 
hour  for  every  y16  in.  in  thickness.  So  that  for  material  8/16  in.  thick, 
a  torch  consuming  about  15  cu.ft.  per  hour  would  be  required,  for 
§  in.  one  consuming  30  cu.ft.,  and  so  on.  However,  it  will  be  found 
that  beginners  obtain  the  best  results  by  using  a  less  powerful  torch 
than  indicated,  whilst  the  more  expert  welder  rapidly  reaches  the  stage 
where  he  can  advantageously  use  a  more  powerful  one,  as  for  example, 
for  V8-in.  material  a  torch  consuming  5.3  cu.ft.;  for  3/16-in.  material 
one  consuming  20  cu.ft. ;  and  for  f-in.  40  cu.ft. 

SIZE    OF    ROD 

The  choice  of  the  right  size  of  welding  rod  is.  of  great  importance. 
A  rod  that  is  too  small  melts  too  freely,  has  a  tendency  to  burn,  and 
is  distributed  badly.  The  defects  of  adhesion  and  oxide  inclusions  are 


LEARNING  TO  WELD  WITH  A  GAS  TORCH 


147 


common.  If  the  wire  is  too  large,  the  rate  of  welding  is  retarded,  the 
molten  bath  is  cooled,  and  it  is  difficult  to  add  the  metal  uniformly. 
In  both  cases  burning  and  overheating  of  the  wrelding  rod  and  material 
are  likely  to  take  place. 

The   following   table   gives   the   sizes   of   rod   for    welding   various 
thicknesses : 


Thickness 

Diameter  of  Wire 

to  be  Welded 

Decimal 

In  Inches 

S.  W.  G. 

Equivalent 

Nearest  1/64 

1/8 

14 

0.081 

5 

5/32  to    3/16 

11 

0.116 

8 

1/4     to     9/32 

8 

0.160 

10 

11/32  to  13/32 

6 

0.192 

12 

above 

4 

0.232 

15 

POSITION    OF    TORCH 

The  flame  of  the  torch  should  be  given  a  definite  inclination.     In 
certain   cases   and  especially  with  expert  welders,   familiar  with  the 


FIG.  107. — Position  of  Torch  and  Rod  for  Backward  Welding. 

backward  method  of  executing  welds,  this  inclination  of  the  flame  to 
the  plane  of  the  weld  is  very  small,  in  other  words,  the  flame  is  almost 
perpendicular  to  the  weld.  However,  it  has  been  found  that  an  angle 
of  20  deg.  gives  the  best  results,  that  is  to  say,  the  angle  between 
the  nozzle  of  the  torch  and  the  perpendicular  should  be  20  degrees, 
the  flame  being  turned  backwards  as  shown  in  Fig.  107.  Beginners 
should  pay  particular  attention  to  obtaining  and  practically  working 
at  this  angle  of  inclination. 

In  welding  backward  it  is  the  welding  rod  that  is  given  a  move- 
ment and  not  the  torch.  The  torch  is  therefore  held  in  such  a  manner 
that  the  flame  advances  along  the  bevelled  faces  with  as  great  a 


148  GAS    TORCH  AND  THERMIT  WELDING 

regularity  as  possible,  the  rate  of  movement  being  in  proportion  to  the 
speed  of  welding.  A  very  slight  transversal  movement  may  be  given 
to  the  torch  to  produce  more  rapid  fusion  of  the  two  bevelled  faces. 
Tho  white  cone  of  the  flame  should  penetrate  very  deeply  into  the 
angle  of  the  V  as  shown  in  Fig.  108.  If  held  too  high  as  shown  in 
Fig.  109  the  melting  at  the  bottom  of  the  V  is  not  sufficient,  the  size 


FIG.  108. — Position  of  Flame.  FIG.  109. — Wrong  Position. 

of  the  weld  is  unnecessarily  increased,  the  metal  near  the  surface  is 
overheated  and  the  speed  of  welding  is  diminished. 

The  penetration  of  the  white  cone  should  be  carefully  observed  if 
the  advantages,  economy  and  quality  of  welds,  which  can  be  obtained 
by  welding  backward  are  required. 

HOW   TO   HOLD    THE   ROD 

The  melting  of  the  metal  is  produced,  as  previously  explained,  be- 
hind the  torch  and  not  in  front  as  is  the  common  practice. 

This  melting  is  not  obtained  by  the  welding  cone  of  the  flame,  but 
by  the  additional  heat  contributed  by  the  envelope  of  the  flame,  the 
torch  being  inclined  towards  the  rear,  in  other  words,  towards  the 
welding  wire. 

The  position  of  the  welding  rod  and  its  movement  should  be  closely 
followed.  The  rod  is  inclined  to  the  line  of  welding,  in  the  advancing 
direction,  that  is  to  say,  in  the  opposite  direction  to  the  inclination 
of  the  flame.  The  best  angle  of  inclination,  between  the  weld  and  the 
rod,  has  been  found  to  be  45  deg.  for  material  about  |-in.  thick,  and 
for  thinner  material,  say  £-in.,  an  angle  of  about  30  degrees.  This  in- 
clination is  maintained  whilst  the  welding  rod  is  given  its  proper  move- 
ment in  the  line  of  welding.  This  movement  for  the  thicker  material, 
say,  about  }-in.,  consists  in  alternately  moving  the  molten  extremity 
of  the  wire  from  one  side  to  the  other  of  the  line  of  welding,  as  shown 


LEARNING  TO   WELD   WITH  A  GAS  TORCH  149 

in  the  small  illustration  in  Fig.lOT.  The  movement  for  material  less 
than  this  thickness  becomes  first  of  all  ellipsoidal  or  gyratory,  and  then 
for  material  about  J-iu.,  and  especially  when  the  material  is  about  yie 
in.,  the  movement  is  translated  into  a  reciprocating  one  without  any 
transversal  movements,  as  shown  in  Fig.  110.  In  both  of  these  cases 
the  extremity  of  the  wire  remains  continually  in  the  molten  bath. 

In  order  that  the  line  of  welding  should  present  an  homogeneous 
appearance,  it  is  advisable  to  operate  in  the  manner  already  laid  down 
and  with  the  same  speed  at  the  commencement  and  completion  of  the 
work.  If,  say,  one  of  the  extremities  of  the  weld  is  attacked  too 
soon  with  the  torch,  free  fusion  and  regular  advancement  are  not 
obtained  until  after  a  certain  time,  with  the  result  that  irregularities  are 
noticeable  at  the  beginning  of  tho  wreld.  To  avoid  this  the  plates 
should  be  preheated  for  a  length  of  a  few  inches  with  the  torch,  so  as 
to  obtairy,  at  the  beginning,  regularity,  and  a  normal  rate  of  welding. 


FIG.  110. — Rod  Movement  When  Welding  Thin  Metal. 

The  torch  and  the  welding  rod  being  held  in  the  manner  indicated,  the 
cone  of  the  flame  is  directed  so  as  to  well  penetrate  into  the  angle 
of  the  bevel,  and  the  first  molten  bath  is  obtained  by  giving  the  torch 
a  slight  gyratory  movement,  immediately  after  which  the  extremity 
of  the  welding  rod  is  introduced  into  the  molten  bath  and  the  torch 
is  then  given  its  regular  advancing  movement. 

The  welding  rod,  on  the  other  hand,  follows  immediately  after  the 
flame,  and  describes  a  reciprocating  or  a  more  or  less  elliptical  and 
longitudinal  motion,  according  to  the  thickness  of  the  metal,  as  indi- 
cated and  shown  in  Figs.  107  and  110.  taking  care  to  always  maintain 
the  given  angle  of  inclination.  The  weld  is  thus  obtained  in  a  normal 
and  very  continuous  manner.  Care  must  be  taken  to  use  a  welding 
rod  which  satisfactorily  fills  the  lines  of  welding,  without  excess  or 
insufficient  addition  of  material.  If  necessary,  the  position  of  the 
torch  is  changed  when  the  extremity  of  the  weld  is  reached  in  order 
to  obtain  a  clean  finish  as  is  usual  with  the  ordinary  method  of 
welding. 

The  melted  metal  being  attacked  in  the  rear,  as  a  result  of  the 
inclination  of  the  flame,  the  bevelled  faces  are  always  well  melted; 


150  GAS  TORCH  AND  THERMIT  WELDING 

the  weld  is  what  is  commonly  said  to  be  well  penetrated  and  the 
defect  of  adhesion  is  almost  impossible.  However,  it  is  advisable  not 
to  travel  too  fast  so  as  to  give  the  bevelled  surface  sufficient  time  to 
melt  freely,  otherwise  candles  of  molten  metal  will  appear  on  the 
underside  of  the  weld  as  a  result  of  the  addition  of  too  much  heat 
at  the  bottom  of  the  V. 

From  the  point  of  view  of  good  penetration  of  the  metal  and  the 
absence  of  the  defect  of  adhesion,  welding  backward  offers  considerable 
advantage  over  other  methods  of  executing  welds  and  is  capable  of 
entirely  eliminating  these  defects. 

Etching  tests  on  welds  obtained  by  this  method  show  perfect  join- 
ing between  the  metal  of  the  plate  and  the  added  metal.  The  welds 
show  distinctly  less  oxide  inclusions  than  those  obtained  by  the  or- 
dinary methods,  and  are  free  from  blowholes.  In  addition  they  possess 
ordinary  hardness  and  the  remaining  mechanical  properties  are  more 
regular. 

Bending  tests  have  given  good  results.  It  is  possible  to  fold  the 
weld  without  starting  a  crack,  which  is  a  very  good  indication  of 
excellent  elongation  properties  and  good  penetration  of  the  weld.  The 
tensile  strength  of  the  weld  is  also  greater  than  that  of  ordinary  welds 
and  improvement  in  the  other  mechanical  properties  is  obtained. 

INSTRUCTIONS  FOR  LEAD  BURNING 

The  "Eveready"  instruction  book,  issued  by  the  Oxweld 
Acetylene  Co.,  gives  the  following  hints  on  lead  burning: 

The  size  of  the  flame  used  in  lead  burning  depends  almost  entirely 
upon  the  class  of  work.  The  0-H3  and  1-H3  tips  are  Used  on  very 
light  sheet  lead  and  similar  work,  the  2-H3  tip  on  heavy  sheet  and 
light  storage  battery  work,  and  the  3-H3  and  4-H3  tips  on  general 
storage  battery  work. 

In  all  cases  where  lead  burning  is  to  be  done,  it  is  essential  that  the 
edges  of  the  parts  to  be  burned  are  first  cleaned.  Otherwise  a  film 
of  oxide  will  form  on  the  molten  surfaces  of  the  metal,  which  will 
tend  to  keep  the  metal  from  flowing  together,  slow  down  the  work 
and  quite  possibly  result  in  a  poor  joint.  Clean  the  edges  to  be  joined 
and  also  clean  the  surface  a  short  distance  back  from  the  edges,  either 
with  a  lead  scraper  or  a  wire  brush. 

It  is  extremely  difficult  to  burn  lead  which  has  been  subjected  to 
the  action  of  a  strong  acid,  such  as  the  sulphuric  acid  used  in  storage 
batteries.  Where  it  is  possible  to  neutralize  the  acid  by  a  solution  of 
ammonia  or  sodium  bicarbonate  without  getting  any  into  the  battery 
and  injuring  it,  that  method  is  allowable.  It  is  decidedly  better  in 
all  cases,  however,  to  wipe  dry  the  parts  to  be  burned  and  then  scrape 
them  bright.  The  scraping  will  remove  the  layer  of  lead  which  has 
been  affected  by  the  acid  and  will  insure  a  good  joint. 


LEARNING  TO  WELD  WITH  A  GAS  TORCH  151 

LEAD  BURNING-STICKS   OR  WELDING  RODS 

In  some  cases  additional  metal  is  fused  in  to  completely  fill  the 
parts  being  burned  or  for  reinforcing  the  joint.  Where  extra  metal 
is  added,  the  "burning  sticks"  or  rods  employed  for  this  purpose  are 
either  pure  lead  or  lead  containing  a  percentage  of  antimony.  Pure 
lead  rods  are  preferable  for  working  on  sheet  lead  or  for  any  part 
which  may  be  subject  to  bending  strains.  Rods  containing  antimony  are 
preferable  where  the  work  is  to  be  threaded  or  where  it  must  be 
rigid  enough  to  withstand  twisting  strains,  as  for  instance  storage 
battery  terminal  posts. 

Hold  the  torch  so  that  the  flame  is  almost  perpendicular  to  the 
surface  of  the  work  and  the  white  cone  almost  touches  the  metal.  Be 
careful,  however,  not  to  jab  the  tip  of  the  torch  in  the  molten  lead,  and 
under  no  circumstances  hold  the  torch  tip  any  closer  to  the  work  than 
may  be  necessary  to  play  the  tip  of  the  inner  cone  of  the  flame  upon 
it.  In  all  lead  burning  it  must  be  remembered  that  the  melting  point 
of  lead  is  low  and  that  as  soon  as  it  reaches  the  melting  point  it  will 
flow  rapidly  and  unless  care  is  exercised  it  may  get  beyond  the  control 
of  the  operator.  The  chief  thing  to  learn  is  to  know  when  the  lead 
is  flowing  properly  and  to  lift  the  flame  immediately  from  that  part  of 
the  work  so  that  no  excess  melting  will  be  done.  Should  the  metal 
start  to  run  away,  lift  the  torch  and  allo\v  the  work  to  cool  before 
attempting  to  proceed. 

When  adding  metal  the  torch  flame  should  be  played  simultaneously 
on  the  rod  and  along  the  edges  of  the  work  to  be  joined  so  that  they 
will  reach  the  fusion  point  at  the  same  time.  It  does  no  good  to 
deposit  molten  lead  upon  cold  lead.  All  the  lead  must  be  melting, 
otherwise  it  will  not  fuse  together. 

Do  not  allow  the  rod  to  touch  the  metal  being  worked  upon,  as  it 
will  probably  stick  and  become  firmly  attached. 

LAP  JOINTS 

In  burning  sheet  lead  it  is  always  better,  wherever  possible,  to  lap 
the  joints,  that  is,  lay  the  edge  of  one  sheet  of  lead  £  to  %  in.  over  the 
edge  of  the  other.  The  overlap  of  both  sheets  must  be  thoroughly 
cleaned,  not  merely  the  edges  of  the  sheets.  After  placing  the  sheets 
in  position  tap  lightly  with  a  wooden  mallet  along  the  line  of  lap  to 
bring  the  two  sheets  together.  Though  lapped  joints  are  sometimes 
burned  without  the  use  of  burning  sticks,  they  are  not  so  strong  as 
when  a  filler  is  used.  In  the  former  method  the  torch  flame  is  merely 
played  along  the  edge  of  the  overlapping  sheet.  With  a  little  practice, 
this  class  of  joint  can  be  made  at  high  speed. 

BUTT  JOINTS 

When  the  edges  of  the  work  are  butted  together  (not  lapped),  it  is 
possible  to  burn  them  together  without  the  addition  of  metal.  Although 
this  makes  a  very  neat  appearing  joint  the  use  of  the  rod  will  insure 


152  GAS  TORCH  AND  THERMIT  WELDING 

a  stronger  joint  with  less  chance  of  leaving  unburned  spots  in  the 
seam.  For  a  butt  joint,  the  sheets  must  be  cut  true  and  must  lie  true 
while  being  burned.  Tapping  along  the  line  of  burning  with  a  wooden 
mallet  about  6  in.  ahead  of  the  burn  is  desirable. 

In  tacking,  burn  a  small  spot  at  each  end  of  the  seam  and  if  it  is 
a  long  one,  burn  small  spots  at  about  6-in.  intervals  to  keep  the  edges 
from  pulling  apart.  This  is  especially  important  on  vertical  seams,  but 
it  is  also  desirable  on  horizontal  seams  to  prevent  trouble  that  may 
be  caused  by  the  edges  spreading. 

The  movement  or  play  of  the  torch  flame  is  largely  a  matter  of 
choice  on  the  part  of  the  operator.  Some  operators  prefer  a  slight 
circular  movement,  progressing  along  the  line  to  be  burned,  while 
others  prefer  to  play  the  flame  alternately  from  each  side  of  the  line 
of  burning.  For  the  beginner,  the  circular  movement  is  probably  the 
better. 

In  burning  horizontal  seams  lapped  or  butted  joints  may  be  used, 
and  it  is  desirable  to  tack  before  burning.  If  extreme  strength  is 
desired,  use  the  lap  joint.  In  vertical  seams  lapped  joints  should  be 
used,  and  should  be  tacked  before  burning.  Start  from  the  bottom  and 
work  upward.  For  overhead  seams  lapped  joints  should  be  used  and 
should  be  tacked  before  burning.  These  seams  require  skill  on  the  part 
of  the  operator,  and  considerable  practice  \vill  be  found  necessary  before 
good  burning  and  neat  results  are  obtained. 

STORAGE  BATTERY  BURNING 

In  battery  repair  work  there  are  several  operations  that  call  for 
lead  burning.  It  should  be  noted  that  great  care  must  be  used  to  see 
that  the  work  is  thoroughly  scraped  bright  before  burning  and  that 
all  oxide  and  traces  of  acid  are  removed.  For  rods,  use  antimonial 
lead  if  certain  that  the  plate  connectors  are  made  of  antimonial  lead ; 
if  uncertain,  use  pure  lead. 

Note:  Antimonial  lead  after  scraping  has  a  silvery  appearance  as 
compared  with  the  blue  tinged  color  of  pure  lead.  Antimonial  lead 
is  also  much  tougher  and  harder  to  scrape  or  pare  with  a  lead  scraper 
or  knife. 

In  burning  plates  to  plate  connectors,  set  up  the  plates  in  a  burning 
rack  or  comb,  which  will  provide  for  proper  spacing  and  true  align- 
ment. The  lugs  of  the  plates  must  extend  above  the  top  of  the  comb. 
Place  the  post  in  position  before  attempting  to  burn  the  lugs  together 
on  a  lead  strap.  To  burn,  play  the  flame  along  the  ends  of  the  lugs 
and  when  they  are  molten  add  metal  from  the  rod  and  form  a  strap 
connecting  them  all  and  the  post.  A  comparatively  large  flame  should 
be  used  to  insure  perfect  joints  because  the  plates  must  be  fused 
perfectly  to  the  strap  and  post. 

If  a  slotted  plate  strap  or  connector  is  used,  set  up  the  plates  as 
described  above  with  the  lugs  extending  up  into  the  slots.  To  burn, 
play  the  flame  along  the  sides  of  the  slots  to  bring  them  and  the 


LEARNING  TO   WELD  WITH  A  GAS  TORCH  153 

lugs  to  a  melting  point  at  the  same  time,  then  add  metal  from  the 
rod  to  fill  up  the  slots  and  flush  the  strap  off  smooth. 

BURNING  CELL  CONNECTORS  OR  TERMINALS  TO  TERMINAL 

POSTS 

The  connectors  should  be  tapped  lightly  with  a  small  wooden 
mallet  until  they  fit  snugly  around  the  terminal  posts.  To  secure  a 
good  burn,  it  is  necessary  that  the  surface  of  the  top  of  the  terminal 
post  be  about  |  in.  below  the  top  surface  of  the  cell  connector  or 
battery  terminal.  If  necessary,  the  post  should  be  cut  off  to  insure 
this  feature.  To  burn,  play  the  flame  on  the  top  of  the  post  and  bring 
it  and  the  inner,  wall  of  the  connector  to  a  molten  state,  forming  a 
molten  pool.  To  this  add  metal  from  the  lead  rod.  As  the  pool  fills 
up,  be  sure  to  watch  that  the  metal  on  the  inside  wall  of  the  con- 
nector flows  into  and  with  the  added  metal.  Continue  until  the  added 
metal  is  flush  with  the  top  surface  of  the  connector.  Then  allow  the 
connector  or  terminal  to  cool  sufficiently  so  that  the  lead  will  not 
crumple  when  brushed,  clean  the  top  with  a  wire  brush,  and  again 
apply  the  flame  and  add  enough  lead  to  smooth  off  and  finish  the  job. 

It  is  sometimes  impossible  to  burn  on  a  connector  or  terminal  in 
one  complete  operation,  because  the  metal  surrounding  the  cavity  be- 
comes overheated.  In  such  cases,  stop  work  as  often  as  the  lead 
seems  to  be  running  too  rapidly,  and  allow  it  to  cool  before  proceeding. 

In  burning  on  a  terminal  in  which  the  end  of  a  cable  is  imbedded, 
protect  the  rubber  insulation  on  the  cable  with  a  strip  of  wet  cloth, 
to  avoid  burning  it. 

In  battery  repair  shops  it  is  often  necessary  to  build  up  a  terminal 
post  which  was  drilled  out  when  the  battery  was  torn  down.  When 
building  up  a  post,  a  mould  should  be  used  to  hold  the  metal  in  place. 
This  mould  can  be  made  of  sheet  metal  and  should  be  tapered  so  as 
to  be  easily  withdrawn  from  the  finished  work.  Be  sure  that  the 
top  of  the  post  is  in  a  molten  state  before  adding  lead,  so  that  the 
post  and  the  metal  added  will  be  solidly  fused.  Unless  this  is  done, 
the  joint  will  be  weak. 

LEAD  BURNING  DATA 

Approximate  results  obtained  with  Eveready  Lead  Burning  Torch: 
PRESSURE  GAS  CONSUMPTION 


Oxygen 

Acetylene 

Oxygen 

Acetylene 

Ib.  per 

Ib.  per 

cu.ft. 

cu.ft. 

SIZE  OF  TIP 

sq.in. 

sq.in. 

per  hour 

per  hour 

0-H3 

2  to  3 

2  to  3 

1 

1 

1-H3  

.  2  to  3 

2  to  3 

2 

2 

2-H3  , 

,  2  to  3 

2  to  3 

3  to    5£ 

3  to     5 

3-H3 

.  3  to  4 

3  to  4 

6  to  10 

6  to     9 

4-H3  

.  3  to  5 

3  to  4 

9  to  12 

8  to  11 

CHAPTER  X 

MAKING  ALLOWANCE  FOR  EXPANSION  AND 
CONTRACTION 

Through  his  practice  work,  as  already  outlined,  the  be- 
ginner in  welding  has  learned  a  little  about  the  trouble  that 
expansion  and  contraction  may  cause  when  proper  allowance 
is  not  made.  This  was  shown  to  some  extent  when  he  at- 
tempted to  butt-weld  two  plates  set  close  together.  The 
remedy  in  that  case  was  to  allow  for  the  contraction  of  the 
cooling  metal  and  weld,  by  diverging  the  edges  of  the  plates. 
From  this  example  alone  he  can  get  a  slight  idea  of  the  tre- 
mendous stresses  often  set  up  when,  for  instance,  a  broken 
spoke  in  a  flywheel  is  welded  without  proper  allowance  being 
made  for  the  amount  of  expansion  in  heating  and  contraction 
in  cooling.  These  stresses  may  be  so  great  as  to  quickly  cause 
other  fractures,  or  be  .of  such  a  nature  as  to  cause  the  sub- 
sequent destruction  of  the  wheel.  Different  metals  conduct 
heat  with  varying  degrees  of  speed,  that  of  copper  being 
much  more  rapid  than  that  of  steel.  On  this  account  the 
welder  must  know  something  of  the  characteristics  of  the 
metal  he  is  working  on  in  order  to  obtain  good  results.  How- 
ever, except  for  the  amount  of  expansion  and  contraction,  the 
same  general  rules  apply  to  all  cases.  It  should  be  kept  in 
mind  at  all  times,  that  nothing  can  prevent  this  expansion  or 
contraction  of  metals  when  heated  or  cooled,  and  that  allow- 
ance in  one  way  or  another  must  always  be  made. 

Where  the  ends  of  a  broken  bar  are  butt-welded  together 
the  parts  are  free  to  expand  as  they  are  heated,  unless  rigidly 
held.  Suppose,  however,  that  they  are  free  to  move,  then 
when  heated  the  broken  ends  will  move  toward  each  other, 
pushing  the  two  parts  of  the  bar  in  opposite  directions  when 
the  heated  ends  touch.  After  the  weld  is  complete,  the  cooling 
will  cause  the  metal  to  contract,  drawing  the  two  parts  of  the 

154 


ALLOWANCE  FOR  EXPANSION  AND  CONTRACTION     155 

bar  closer  together.  In  some  cases  the  bar  may  be  shorter  than 
before,  depending  on  the  care  and  skill  with  which  the  weld 
was  made.  Owing  to  the  fact  that  the  parts  of  the  bar  are 
free  to  move  no  bad  stresses  are  set  up.  Again  suppose  the 
bar  happened  to  be  part  of  a  frame,  as  shown  in  Fig.  111. 
Then  when  heated  at  the  break  A,  the  ends  could  only  move 
toward  each  other,  in  certain  cases  causing  these  ends  to 
upset,  or  become  thicker.  After  the  weld  was  completed,  the 
metal  would  start  to  contract,  the  tendency  being  to  pull  the 
cross  ends  in  as  shown  at  B  and  C.  If  the  metal  was  ductile 
— that  is,  would  stretch — it  would  probably  actually  bend  in 
as  suggested.  Wrought  iron  or  steel,  for  example,  would 


FIG.  111. — Broken  Frame  with  Preheating  Zones  Indicated. 

probably  do  this.  Cast  iron  would  probably  break.  Aluminum 
would  break  or  bend,  according  to  the  alloy  used.  In  any 
case  it  would  be  a  poor  job,  no  matter  how  well  the  welding 
work  itself  was  performed.  The  way  to  obtain  a  good  job  is 
to  heat  the  frame  at  D  and  E,  so  that  these  side  bars  will 
expand  as  much  as  the  middle  one  will  while  being  welded. 
The  contraction  on  cooling  will  then  be  the  same  on  all  three. 
Local  heating  like  this  is  not  always  sufficient,  and  it  is  often 
necessary  to  heat  the  whole  piece. 

Sometimes  conditions  are  such  that  neither  a  part,  nor  the 
whole  of  a  piece  may  be  heated  properly. 

We  may  then  use  a  jack  to  open  the  break  in  the  middle 
bar  a  short  distance,  make  the  weld,  and  then  slowly  loosen 
the  tension  on  the  jack  as  the  metal  contracts.  Or  we  may 


156 


GAS  TORCH  AND   THERMIT  WELDING 


wrap  wet  cloths  or  wet  asbestos  or  clay  around  the  middle  bar, 
close  to  the  weld  and  keep   cold  water  running  on  it  while 


FIG.  112. — Preheating  Furnace,  Using  Charcoal. 

welding.  This  simply  holds  the  expansion  to  a  limited  area 
and  should  be  employed  only  when  no  other  method  is  possible. 
Undoubtedly  the  better  method  in  nearly  all  cases  is  the  pre- 


FIG.  113. — Preheating  Furnace  on  an  Iron  Table. 

heating  of  the  article  or  a  portion  of  it,  though  in  each  case 
proper  judgment  must  be  exercised. 

The  simplest  way  to  preheat  work  is,  as  a  rule,  to  build  a 
temporary  firebrick  charcoal  furnace,  the  form  depending  on 


ALLOWANCE   FOR  EXPANSION   AND   CONTRACTION      157 

the  shape  of  the  work.  Where  a  piece  like  the  frame  just  men- 
tioned is  to  be  heated  all  over,  a  furnace  something  like  the 
one  shown  in  Fig.  112  is  very  handy.  Often  an  iron  table  and 
furnace  like  the  one  shown  in  Fig.  113  will  serve  for  numerous 
repair  jobs. 

USING  HEATING  TORCHES 

Where  the  nature  of  the  work  makes  the  use  of  charcoal 
unsuitable  or  impossible,  a  coal  gas  torch,  kerosene  torch,  or 


FIG.  114. — Crude  Oil  or  Kerosene  Preheater  in  'Action. 


FIG.  115. — Using  Two  Burners  to  Preheat  a  Large  Gear. 

even  the  welding  flame  itself,  may  be  used.     The  last,  however, 
is  too  expensive  to  use  except  where  absolutely  necessary.    As  a 


158 


GAS  TORCH  AND  THERMIT  WELDING 


rule,  a  coal  gas  torch  makes  a  very  satisfactory  means  of  pre- 
heating if  it  can  be  used.  In  using  any  preheating  flame  it  is 
best  to  build  up  with  firebrick  or  asbestos  in  such  a  way  as  to 
confine  the  heat  where  wanted.  This  also  saves  fuel.  An  OX- 


FIG.  116. — A  Gas  and  Preheating  Torch. 

weld  preheater  using  any  grade  of  fuel,  crude  or  kerosene  oil, 
is  shown  in  action  in  Figs.  114  and  115.  This  has  two  burners, 
and  has  to  be  pumped  so  as  to  have  about  25  to  50  Ib.  pressure 
to  get  good  results.  The  large  size  weighs  110  Ib.  One  big  ad- 
vantage of  a  burner  of  this  type  is,  that  it  may  be  carried  any- 


FIG.  117. — Portable  Electric  Blower- Type  Gas-Burning  Preheater. 

where  and  used.  Where  a  shop  has  a  compressed-air  system 
and  illuminating  gas,  the  type  of  torch  in  Fig.  116  will  prove 
exceedingly  satisfactory.  In  case  a  shop  does  not  have  a  com- 
pressed-air system,  but  has  gas  and  electricity,  the  apparatus 
shown  in  Fig.  117  may  prove  useful.  This  is  made  by  the 


ALLOWANCE  FOR  EXPANSION  AND  CONTRACTION     159 

Tyler  Manufacturing  Co.,  Boston.     The  motor  driving  the  fan 
is  of  the  universal  type,  operating  on  either  alternating  or  direct 


FlG.  118. — Portable  Preheater  Mounted  on  a  Stand. 


FIG.  119.-— Iron  Table  With  Firebrick  Top. 

current.     One  motor  will  supply  air  enough  for  four  regular 
size  burners. 

Another  torch  is  shown  in  Fig.  118.     This  also  uses  illu- 
minating gas,  the  air  being  supplied  by  means  of  an  electric 


160  GAS  TORCH  AND  THERMIT  WELDING 

driven  fan.  This  device  is  made  by  the  North  American  Manu- 
facturing Co.,  Cleveland,  Ohio.  It  is  claimed  that  from  500 
to  2500  deg.  F.  may  be  obtained  with  this  torch. 

For  welding  work  of  all  kinds  where  proper  alignment  must 
be  maintained,  .a  table  with  a  heavy  cast-iron  top  is  almost  in- 
dispensable. Tables  of  this  kind  may  be  obtained  from  almost 
any  of  the  supply  firms.  The  Imperial  Brass  Manufacturing 
Co.,  Chicago,  supplies  a  table  with  a  firebrick  top,  as  shown  in 
Fig.  119.  This  kind  of  a  table  is  very  handy,  as  it  enables  the 
welder  to  construct  firebrick  furnaces  of  all  kinds,  and  to  so  box 
in  his  work  as  to  conserve  all  the  heat  possible.  It  also  brings 
the  work  up  to  where  he  can  work  on  it  to  the  best  advantage. 

COOKING  WORK 

The  cooling  of  steel  or  iron  work  after  welding  is  often  as 
important  as  the  preheating.  Some  work  must  be  annealed 
after  it  has  cooled,  by  heating  to  a  red  heat  and  then  slowly 
cooling  again.  Small  parts  may  be  buried  in  slacked  lime,  ashes 
or  the  like.  Flat  work  may  be  laid  in  a  sheet-iron  box  partly 
filled  with  lime  and  covered  with  sheet  asbestos  or  more  lime. 
In  any  case,  the  weld  should  be  protected  as  much  as  possible 
from  drafts.  Where  a  firebrick  furnace  has  been  built  up  around 
some  part,  it  may  be  closed  in  and  the  work  allowed  to  cool  as 
slowly  as  possible.  The  welder  must  use  good  judgment  in  all 
cases.  It  must  not  be  thought  that  preheating  is  only  necessary 
to  take  care  of  expansion  and  contraction,  for  while  in  small 
work  this  is  often  the  only  consideration,  on  large  work  it  saves 
expense.  By  this  it  is  meant  that  the  use  of  charcoal,  gas  or 
other  heating  mediums  is  much  cheaper  than  to  try  to  bring 
the  parts  to  be  joined  up  to  a  welding  heat  with  the  welding 
flame  alone. 

The  way  in  which  expansion  and  contraction  will  take  effect 
often  requires  considerable  study.  If  the  work  can  be  heated 
all  over,  this  is  often  the  best  way.  As  already  mentioned, 
this  is  often  not  possible,  so  in  order  to  assist  the  beginner,  a 
number  of  examples  will  be  given  showing  just  where  certain 
jobs  should  be  preheated  to  get  good  results.  A  good  thing  to 
keep  in  mind  as  to  where  to  preheat,  is  to  imagine  a  wedge 
driven  in  at  the  break  and  note  what  places  this  action  would 
put  under  strain. 


ALLOWANCE   FOR  EXPANSION   AND   CONTRACTION     161 


THE  WIEDERWAX  PREHEATER 

A  preheating  furnace  suitable  for  both  preheating  and  slow 
cooling  is  shown  in  Figs.  120  and  121.     This  heater  is  made 


FiG.  120. — The  Wiederwax  Preheater. 


FIG.  121. — Showing  the  Slow  Cooling  Oven. 

by  the  Geist  Manufacturing  Co.,  Atlantic  City,  N.  J.,  and  is 
known  as  the  Wiederwax  pr cheater.     It  has  eight  gas  burners 


162 


GAS  TORCH  AND  THERMIT  WELDING 


entering  from  each  end  and  extending  to  the  middle.  This 
makes  it  possible  to  heat  any  section  or  all  of  the  top,  as  desired. 
The  top  has  parallel  grate  bars  to  support  the  work  and  the 
gas  burners  are  buried  in  pieces  of  refractory,  heat-retaining 
material,  so  that  parts  are  heated  with  the  use  of  a  minimum 
amount  of  gas.  After  the  welding  is  done,  the  work  is  placed 
in  the  oven  underneath  the  heaters  and  slowly  cooled. 

When  using  this  heater  or  welding  at  any  time,  the  work 
should  be  covered  with  asbestos  sheet  as  much  as  possible. 

This  concern  also  makes  a  floor-type  of  preheater  for  heavy 
work. 

SUGGESTIONS  REGARDING  THE  WELDING  OF  GRATINGS  AND 

PULLEYS 

S.  W.  Miller,  of  the  Rochester  Welding  Works,  writing  in  the 
"American  Machinist"  says: 

It  should  be  clearly  understood  by  the  welder  that  in  a 
restrained  weld,  which  is  one  entirely  surrounded  by  metal,  such 


FIG.  122. — A  Restrained  Weld.  FIG.  123. — Grating  to  be  Welded. 

as  a  crack  in  the  center  of  a  plate,  it  is  impossible  to  get  rid 
of  both  strain  and  distortion;  a  moment's  thought  will  make 
this  clear.  Such  a  crack  is  shown  in  Fig.  122.  When  crack  A 
is  welded  the  metal  between  B  and  C  is  heated  hotter  than  that 
between  D  and  E,  and  F  and  G,  and,  being  soft,  the  expansion 
crushes  it;  so  when  cooling  occurs,  B  to  C  contracts  more  than 
the  rest  of  the  plate,  which  either  causes  a  crack,  or  leaves  a 
tensile  strain  in  the  plate.  It  is  true  that  the  strain  can  be  re- 
lieved by  annealing,  but  that  leaves  a  distortion  of  some  kind; 
if  the  distance  BC  be  the  same  as  originally,  the  thickness  along 
BC  must  become  less,  and  vice  versa. 

If  this  is  not  clear,  let  the  welder  heat  a  spot  in  the  center 
of  a  4-in.  plate  of  steel,  and  see  what  happens. 

In  a  partly  restrained  weld,  such  as  Fig.  Ill,  it  is  evident 


ALLOWANCE  FOR  EXPANSION  AND  CONTRACTION     163 


that  the  method  of  preheating  described  produces  expansion  of 
the  part  to  be  welded  in  such  a  way  that  the  opening  of  the 
crack  is  the  same  at  all  points  in  its  length.  In  other  words, 
there  is  no  variation  in  the  width  of  the  crack  after  expansion 
and  before  welding. 

This  is  an  important  principle  to  be  noted  in  expansion  and 
contraction  problems;  it  may  be  worded  as  follows:  A  crack 
must  always  be  opened  the  same  amount  at  every  point  in  its 
length,  if  both  strain  and  distortion  are  to  be  avoided. 

Fig.  123  shows  the  condition  of  a  grating  when  received  at 
the  welding  shop.  The  quickest  and  cheapest  way  to  weld  this, 
if  three  men  are  available,  is  to  double  bevel  all  breaks;  use 
three  men  to  weld  A,  B  and  D  at  the  same  time,  first  on  one 
side  and  then  on  the  other;  clamp  the  piece  on  a  flat  table  to 


/Heating  Zone 


FIG.  124. — Result  of  Improper 
Heating. 


We/cfB 

FIG.  125. — Welding  a  Broken 
Pulley. 


keep  it  straight  and  let  it  cool.  Then  have  one  man  heat  at  E 
with  a  torch,  and  let  another  weld  at  C  as  at  the  other  points. 

If  only  one  man  is  at  hand,  he  should  weld  D  first ;  then, 
keeping  bar  D  hot,  weld  B;  next,  keeping  both  B  and  D  hot, 
weld  A;  allow  the  piece  to  cool,  heat  E  and  weld  C  as  before. 

This  brings  out  the  principle  that  one  should  never  finish 
a  weld  in  the  center  of  a  piece,  unless  it  is  absolutely  necessary; 
always  finish  at  the  edge. 

It  will  be  seen  that  the  method  just  described  keeps  the  sides 
of  the  cracks  parallel,  and  that  if  the  proper  allowance  is  made 
for  contraction,  there  will  be  no  strains  left  in  the  welded  piece. 

The  matter  may  be  made  clearer  by  a  study  of  Fig.  124, 
which  indicates  the  result  of  improper  heating.  Heating  the 
corner  H  for  crack  B  will  lengthen  sides  A  and  C,  the  resultant 
of  these  being  in  the  direction  of  Z>;  so  that  the  upper  part  of 


164  GAS  TORCH  AND  THERMIT  WELDING 

crack  B  will  lie  as  in  the  dotted  lines,  and  after  welding  and 
cooling  there  will  be  strains  at  E,  F  and  G  which  will  surely 
cause  cracks  in  service,  if  not  at  once. 

With  a  smaller  grating  it  is  possible  that  there  would  be 
spring  enough  in  the  bars  to  avoid  breakage;  but  there  would 
be  strains  that  could  be  avoided  by  other  methods.  The  basic 
principle  of  all  welding  is  to  weld  without  having  either  strain 
or  distortion  in  the  finished  piece. 

With  regard  to  pulley  welding  such  as  shown  in  Fig.  125, 
the  rim  should  be  heated  on  both  sides  of  the  broken  spoke  to 
lengthen  the  rim  and  pull  the  crack  A  open,  and  the  spoke 
should  be  kept  as  cold  as  possible.  Also  all  spokes  should  be 
welded  from  both  sides. 

The  break  at  B  should  be  opened  by  heating  the  spokes  next 
to  it  so  that  when  the  crack  is  open  enough,  the  edges  of  the 
break  will  be  the  same  distance  from  the  center;  this  of  course 
means  different  amounts  of  heat  in  the  two  spokes. 

AUTOMOBILE  CYLINDER  WORE 

The  next  example  is  a  block  of  two  cylinders,  broken  as 
indicated  in  Fig.  126.  The  first  break  to  be  repaired  is  in  the 
water  jacket  at  A.  The  second  break  is  on  the  flange  at  B,  and 
the  third  is  on  the  water  jacket  as  shown  at  G.  The  fourth 
crack  D  is  on  the  inside  of  the  water  jacket,  necessitating  the 
removal  of  part  E  by  drilling  in  order  to  get  at  it. 

To  weld  any  of  these  cracks,  except  B,  without  preheating 
would  break  the  casting  from  expansion  when  the  flame  was 
applied  to  it,  and  contraction  when  the  weld  cooled.  The  pre- 
heating in  this  case  means  the  heating  of  the  entire  casting 
alike.  To  do  this,  build  a  furnace  of  firebrick,  as  shown  at  F. 
In  order  to  give  enough  draft  for  the  fire,  the  bottom  bricks 
should  be  set  about  1  in.  apart,  The  cylinder  block,  with  the 
cracks  properly  chipped  and  beveled,  may  then  be  placed  on 
the  first  layer  of  brick  and  the  walls  built  up  around  it.  These 
walls  should  be  so  built  as  to  allow  about  6  in.  between  them 
and  the  cylinder.  That  is,  there  should  be  space  enough  allowed 
to  turn  the  cylinder  without  knocking  down  the  walls  when 
ready  to  weld.  About  three  or  four  shovelfuls  of  charcoal  should 
be  put  around  the  cylinder  and  a  little  kerosene  put  on  it  and 
lighted.  After  the  charcoal  has  become  thoroughly  lighted  and 


ALLOWANCE  FOR  EXPANSION   AND  CONTRACTION     165 

the  cylinder  slightly  heated,  more  charcoal  should  be  added  until 
half  the   casting  is   covered.     Then  a  piece  of  sheet  asbestos 


Finished* 
Weld       \ 


--~ -Air  Holes  / 

FIG.  126. — Broken  Motor    Cylinder  Block  and  Preheating  Furnace. 

should  be  put  over  the  top,  and  a  few  holes  punched  in  it  for 
draft.    Where  the  break  is  bad,  leave  the  cylinder  alone  until 


166  GAS  TORCH  AND   THERMIT   WELDING 

it  reaches  a  dark  red  all  over,  then  remove  the  asbestos  and 
turn  the  cylinder  so  that  the  part  to  be  welded  first  is  upper- 
most. Then  replace  the  asbestos  and  cut  a  hole  in  it  so  that 
the  break  can  be  reached  with  the  torch  and  welding  rod.  Never 
take  the  cylinder  out  of  the  fire  to  weld. 

In  working  on  automobile  cylinders  it  is  usually  unnecessary 
to  preheat  at  all  when  welding  lugs;  in  cases  where  it  is  neces- 
sary, only  a  very  slight  amount  is  needed — just  enough  so  the 
cylinder  cannot  be  handled  without  tongs. 

Usually  ordinary  jacket  cracks  can  be  welded  at  much  less 
than  a  red  heat.  In  fact  if  a  red  heat  is  used,  in  most  cases 
the  cylinder  bores  will  warp  badly. 

The  important  points  in  cylinder  welding  are  a  uniform 
soaking  heat,  not  necessarily  very  high,  welding  on  rising  tem- 
perature, and  slow  cooling. 

Never  weld  an  important  break  in  a  cylinder  block  without 
about  three  hours  slow  preheating,  never  allowing  the  fire  to 
die  down.  Then  pack  it  in  loose  asbestos  in  the  fire,  to  insure 
slow  cooling.  Of  course,  there  are  exceptional  cases  where  the 
break  is  so  bad  that  high  preheating  is  needed. 

Care  must  be  taken  not  to  let  melted  metal  run  down  into 
the  water  jacket.  Be  sure  to  work  out  all  dirt  or  scale,  and  do 
not  leave  any  pinholes  or  blowholes.  In  order  to  prevent  the 
bore  of  the  cylinder  from  scaling,  it  should  be  coated  with  oil 
and  a  thin  coating  of  graphite  applied  before  the  cylinder  is 
placed  in  the  furnace.  After  welding  the  graphite  can  be  cleaned 
off  with  a  piece  of  waste. 

For  crack  B,  the  cylinder  seldom  needs  to  be  preheated,  as 
previously  mentioned.  The  inner  weld  JC  is  made  the  same  as 
crack  A.  Crack  D,  being  on  the  inside  of  the  water  jacket,  is 
treated  differently.  A  portion  of  the  outer  wall  of  the  water 
jacket  is  removed  by  drilling,  as  previously  mentioned.  The  inner 
weld  is  made,  after  which  the  removed  portion  is  replaced  and 
welded.  In  order  to  hold  the  piece  in  place  while  being  welded 
a  cast-iron  rod  may  be  welded  to  it  to  serve  as  a  handle.  After 
the  weld  is  finished,  this  rod  is  cut  off. 

After  the  cylinder  has  been  welded  and  cooled  off,  it  should 
be  tested  to  be  sure  that  the  weld  is  entirely  tight.  Where  it 
is  possible,  this  should  be  tested  with  water  pressure.  If  it  is 
not  possible  to  do  this,  the  water  jacket  should  be  filled  with 


ALLOWANCE   FOR  EXPANSION   AND   CONTRACTION     167 

kerosene,  because  kerosene  penetrates  a  crack  or  a  pinhole  faster 
than  water. 

In  case  any  leaks  are  found,  the  metal  should  be  chipped 
out  at  that  point,  placed  in  the  fire,  and  rewelded  exactly  as 
before. 

The  next  job,  illustrated  in  Fig.  127,  is  typical  of  a  large 
class.  Work  of  this  kind  is  usually  in  cast-iron,  though  occa- 
sionally of  steel,  or  semi-steel.  The  piece  shown  is  a  cast-iron 
shear  arm  broken  where  the  section  is  about  6  or  8  in.  thick 
and  16  in.  across.  In  preparing  a  casting  of  this  size,  the  break 
is  beveled  at  60  deg.  on  each  side,  using  a  12-lb.  sledge  and  a 
handled  chisel.  It  is  then  lined  up  and  a  preheating  firebrick 
furnace  built  around  the  break,  allowing  sufficient  space  for  the 
charcoal  around  the  work.  Then  heat  to  a  bright  red  well  back 
from  the  break.  Two  welders  should  work  on  a  job  of  this  kind, 


-Weld  here 


FIG.  127. — Broken  and  Welded  Shear  Arm. 

each  welding  about  half  an  hour  or  less,  at  a  time.  A  large 
welding  head,  a  long-handled  torch  and  J-in.  welding  rod  are 
used.  Two  rods  should  be  used,  welded  end  to  end.  There 
should  be  plenty  of  rods  and  plenty  of  flux.  There  should 
also  be  a  good  supply  of  asbestos  sheet  and  a  bucket  of  water. 
The  sheet  is  to  keep  in  the  heat  and  to  protect  the  welders, 
and  the  water  is  to  cool  the  torches.  After  the  weld  is  com- 
pleted on  one  side,  and-  while  the  metal  is  still  pretty  hot,  the 
casting  is  turned  over.  The  movement  will  naturally  destroy 
the  firebrick  furnace,  which  has  to  be  rebuilt  again,  the  casting 
heated  up  as  before,  and  the  weld  made.  In  a  job  of  this  kind 
it  is  necessary  to  reinforce  the  weld  on  both  sides.  This  rein- 
forcing should  be  about  J  in.  high.  After  the  welding  is  all 
done,  the  piece  is  heated  up  to  an  even  red  heat  all  around  the 
weld  and  allowed  to  cool  very  slowly. 

In  welding  in  or  building  up  gear  teeth,  as  shown  in  Fig. 


168 


GAS  TORCH   AND  THERMIT  WELDING 


128,  it  is  seldom  necessary  to  preheat.  If  the  gear  is  a  light  one, 
say  about  3  in.  wide  and  with  a  rim  depth  of  not  over  1  in., 
the  job  can  usually  be  done  without  preheating.  However,  pre- 
heating with  some  cheap  fuel  will,  on  large  work,  save  the  more 
expensive  gases.  In  doing  a  job  of  this  kind  the  greatest  care 
must  be  taken  to  start  properly.  The  work  should  be  done  so 


,-Finisbed  Weld^ 


FIG.  128.— Method  of  rilling  in  Gear  Teeth. 

as  to  do  away  with  as  much  machining  as  possible.  Sometimes 
the  tooth  may  be  built  up  about  as  shown  at  A  and  finished  by 
filing  or  otherwise.  At  other  times  it  will  be  necessary  to  weld 
in  on  teeth  each  side  of  the  one  to  be  replaced,  as  shown  at  B. 
Again  it  may  be  possible  to  use  carbon  blocks  and  fill  in  as  shown 
at  C.  In  using  blocks  of  this  kind,  care  must  be  taken  that  there 
is  ample  room  at  the  bottom  for  the  root  of  the  tooth  being 
replaced. 


CHAPTER  XI 
WELDING  VARIOUS  METALS  AND  THE  FLUXES  USED 

The  first  property  to  be  considered  in  welding  various  metals 
is  the  melting  point.  Gas-torch  welding  is  the  joining  together 
of  two  metal  parts  by  fusion  at  the  line  of  contact  and  in  order 
to  secure  a  perfect  weld  it  is  necessary  that  each  part  be  melted, 
and  the  molten  metal  allowed  to  flow  together  and  harden  in 
this  state  of  mixture. 

The  approximate  melting  points  and  other  properties  of  the 
metals  and  alloys  commonly  welded  are  given  in  Table  XVI, 
taken  from  "Oxwelding  and  Cutting." 

When  metallic  bodies  are  subjected  to  an  increase  in  tem- 
perature they  expand  the  rate  of  this  expansion,  being  closely' 
known  for  each  degree  of  rise  in  temperature.  When  the  tem- 
perature is  lowered  a  reverse  action  takes  place,  the  bodies 
contract  and  the  volume  and  linear  dimensions  decrease.  This 
has  been  explained  to  some  extent  in  the  previous  chapter,  and 
examples  given  to  show  the  effects.  Each  metal  has  its  own  co- 
efficient of  expansion,  which  varies  materially  for  the  different 
metals.  As  seen  from  the  table  given,  of  the  metals  most  com- 
monly welded  aluminum  expands  the  most,  bronze  and  brass 
next,  then  copper,  steel,  and  iron.  Aluminum  expands  almost 
twice  as  much  as  iron  or  steel. 

Conductivity  and  Oxidation. — The  conductivity  of  a  metal 
is  its  property  of  transmitting  heat  throughout  its  mass.  This 
property  is  not  the  same  for  all  metals,  and  varies  widely.  It  is 
commonly  called  thermal  conductivity. 

It  can  be  seen  that  if  one  metal  conducts  or  transmits  the 
heat  from  the  torch  flame  more  rapidly  than  another,  it  is 
necessary  that  allowance  be  made  as  to  the  method  of  handling 
the  job,  the  size  of  the  torch,  and  the  nature  of  the  preheating 
equipment  used. 

In  welding  metals  of  high  thermal  conductivity  it  is  neces- 
sary to  use  oversize  tips — as  in  the  case  of  copper  where  the 

169 


170 


GAS  TORCH  AND  THERMIT  WELDING 


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WELDING  VARIOUS  METALS  AND  FLUXES    USED       171 

melting  point  is  low  and  the  conductivity  high.  However,  too 
large  a  flame  is  bad,  because  the  operator  will  not  be  able  to 
correctly  place  the  mass  of  molten  metal.  On  sheet  work  the 
proper  flame  will  melt  the  metal  to  a  width  about  equal  to  the 
thickness  of  the  sheet. 

When  welding  heavy  work  the  operator  should  be  very  care- 
ful not  to  blow  a  part  of  the  molten  metal  on  to  the  colder  por- 
tions as  it  will  make  a  defective  weld  at  that  point  (called  an 
"adhesion").  If  this  should  occur,  the  flame  should  be  played 
over  this  chilled  portion  until  it  is  in  fusion  with  the  molten 
metal. 

Certain  metals  oxidize  more  rapidly  than  others.  Oxidation 
.is  the  reaction  produced  by  the  combination  of  oxygen  with  a 
metal.  The  weld  may  become  oxidized  by  contact  with  the 
oxygen  in  the  air  and  by  the  presence  of  excess  oxygen  in  the 
welding  flame.  An  oxide  has  none  of  the  metallic  properties 
of  the  metal  from  which  it  is  formed.  When  present  in  a  weld 
it  seriously  weakens  it  and  it  is  therefore  very  necessary  that 
it  be  avoided  as  far  as  possible. 

Some  oxides  are  lighter  than  the  metal  itself,  while  others 
are  heavier.  Consequently,  when  a  metal  is  reduced  to  a 
molten  condition  the  oxide  will  either  float  on  the  surface  of 
the  liquid  metal,  remain  suspended,  or  tend  to  sink  toward  the 
bottom. 

The  melting  point  of  oxides  is  in  some  cases  higher,  and  in 
others  lower,  than  that  of  the  original  metals.  This  point  must 
also  be  considered  in  attempting  to  eliminate  oxide  from  a  weld. 

Some  metals  when  molten  also  have  the  property  of  dis- 
solving a  portion  of  the  oxide,  the  extent  of  this  solution  being 
dependent  upon  the  metal  itself.  When  this  is  the  case  the  oxide 
is  retained  in  solution  until  the  metal  hardens,  in  some  cases 
separating  and  producing  a  weakened  weld,  in  others  being 
retained  permanently. 

Oxide  may  be  dealt  with  in  two  ways.  First,  by  taking 
means  to  prevent  its  formation,  by  the  use  of  a  neutral  or  re- 
ducing flame  in  the  torch,  or  by  the  use  of  various  cleaning 
fluxes ;  second,  by  eliminating  the  oxide  after  its  formation  with 
suitable  fluxes,  which  either  dissolve  or  float  it  off,  or  by  mechan- 
ically removing  it  by  the  manipulation  of  the  welding  rod 
or  a  paddle  made  for  this  purpose. 


172  GAS  TORCH  AND   THERMIT  WELDING 

The  subject  of  oxidation  is  one  of  vital  importance  to  the 
welder,  one  that  he  should  study  thoroughly  in  order  to  become 
familiar  with  all  its  forms,  Oxidation  is  the  cause  of  a  great 
majority  of  defective  welds. 

There  are  also  metals,  that,  when  heated  to  the  melting  point, 
have  the  property  of  absorbing  gases  from  the  flame.  When  the 
metals  cool,  the  gases  are  released.  In  a  great  many  cases  the 
release  of  the  gases  occurs  at  a  time  when  the  metal  is  not 
sufficiently  fluid  to  allow  them  to  pass  to  the  air.  Consequently, 
small  bubbles  or  blowholes  are  incorporated  in  the  weld.  Then, 
too,  in  the  welding  of  various  metals  the  force  of  the  torch  flame 
causes  the  molten  metal  to  flow  back  away  from  it.  When  the 
flame  is  withdrawn  the  molten  metal  returns — similar  to  the 
action  of  any  other  liquid.  At  such  times  the  return  of  the 
molten  metal  may  be  so  rapid  that  small  quantities  of  the  gases 
become  entrapped  and  remain  in  the  weld  as  blowholes.  This 
is  a  very  common  occurrence  in  cast-iron  welding. 

In  the  case  of  the  absorption  of  the  gases  by  the  hot  and 
molten  metal,  the  difficulties  may  be  overcome  by  the  use  of 
proper  protecting  and  cleaning  fluxes  and  properly  prepared 
welding  rods. 

In  the  case  of  the  gases  being  entrapped  by  the  molten  metal, 
this  may  be  overcome  by  "working  out"  the  gas  by  means  of 
the  torch  and  welding  rod. 

Vaporization  of  Substances. — In  the  manufacture  of 
metals  substances  are  combined  in  amounts  which  determine  the 
behavior  and  characteristics  of  the  metal.  In  iron  and  steel 
there  is  a  certain  amount  of  carbon,  silicon,  manganese,  phos- 
phorus, sulphur,  etc.  While  these  substances  may  be  present 
in  only  very  small  quantities,  yet  their  elimination,  or  presence 
in  excess,  may  materially  affect  the  mechanical  properties  of  the 
metal. 

The  high  temperature  of  the  welding  flame  may  cause  these 
substances  to  burn  out  or  to  volatilize.  They  can  burn  or  oxidize 
directly  in  the  oxygen  of  the  atmosphere,  in  excess  oxygen  in 
the  welding  flame,  or  by  the  reduction  of  the  oxide  of  the  metal 
formed  in  melting. 

In  the  working  of  brasses,  bronzes,  or  an  alloy  in  which 
zinc  is  present,  it  is  commonly  observed  that  the  zinc  vaporizes 
and  passes  off  as  heavy  white  fumes  in  the  form  of  zinc  oxide. 


WELDING  VARIOUS   METALS  AND   FLUXES  USED       173 

It  can  be  seen  that  when  this  occurs  the  zinc  content  of  the 
alloy  is  materially  reduced,  and  consequently  the  resultant  weld 
will  not  have  the  same  mechanical  and  chemical  properties  as 
the  original  metal.  Special  fluxes  are  provided  to  prevent  this ; 
also,  welding  rods  can  be  obtained  which  will  either  prevent  the 
vaporization  of  the  volatile  substance  or  will  replace  it. 

Separation  of  Elements. — Alloys  are  uniform  mixtures  of 
metals.  The  fusion  of  the  different  elements  composing  an  alloy 
is  carried  out  at  a  certain  fixed  temperature.  In  the  welding 
of  metals 'of  different  kinds,  it  has  been  noted  that  when  some 
of  these  alloys  have  been  heated  to  the  high  temperatures  pro- 
duced by  the  welding  flame  various  substances  separate  or 
segregate  and  that  it  is  impossible  to  secure  a  uniform  weld. 

This  segregation  occurs  quite  frequently  under  the  torch 
flame  and  also  occurs  in  the  manufacture  of  the  metal.  Under 
these  conditions  the  difficulty  of  welding  some  alloys  can  be 
readily  seen. 

Welding  Various  Metals. — With  the  foregoing  facts  and 
suggestions  in  mind  we  will  now  take  up  the  various  metals 
most  frequently  welded,  and  give  directions  that  will  apply  in 
their  special  cases.  The  composition  of  various  fluxes  will  also 
be  given,  but  it  should  be  remembered  that  the  different  acces- 
sory concerns  can  supply  far  more  satisfactory  fluxes  than  can  be 
made  in  small  lots  by  the  individual  user,  and  the  welder  should, 
where  possible,  buy  the  fluxes  needed  and  apply  them  accord- 
ing to  directions.  This  also  applies  to  welding  rods  which 
should  be  bought  from  reliable  concerns  for  certain  specified 
jobs.  For  emergency  work,  where  the  proper  rods  are  not 
available  scrap  material  or  wire  may  be  used,  but  it  is  not  good 
practice.  A  first-class  welder  who  cares  for  his  work  and  his 
reputation  will  use  rods  of  the  proper  chemical  composition  for 
the  work  he  has  to  do.  For  this  purpose  he  should  buy  his 
rods  from  firms  of  established  reputation,  who  are  not  afraid 
to  advertise  their  output. 

Welding  Aluminum. — Aluminum  parts  to  be  welded  may 
be  divided  into  two  classes — those  made  of  drawn  or  rolled 
aluminum  and  those  which  are  cast. 

Rolled  aluminum  is  usually  98  per  cent  pure  or  better,  the 
main  impurities  being  silicon  and  iron.  Aluminum  as  pure  as 
this  is  seldom  used  for  castings,  since  its  strength  is  considerably 


174  GAS  TORCH  AND  THERMIT  WELDING 

less  than  that  of  various  alloys.  Zinc  in  amounts  ranging  from 
5  to  25  per  cent,  but  usually  about  10  per  cent,  was  often  used 
in  the  past,  but  the  alloy  was  so  brittle  just  below  solidification 
that  a  large  number  of  castings  were  defective  owing  to  shrink- 
age cracks.  A  copper  alloy  is  now  more  commonly  used,  the 
copper  content  being  less  than  15  per  cent,  7  per  cent  probably 
being  the  favorite.  This  is  not  so  strong  at  ordinary  tempera- 
tures as  the  zinc  alloy,  but  it  does  not  have  such  a  tendency  to 
crack.  This  makes  it  much  better  for  welding  as  well  as  for 
casting,  especially  on  complicated  work. 

Aluminum  oxidizes  easily  in  the  air,  especially  at  high 
temperatures,  and  in  the  latter  condition  the  oxide  coating  is 
quite  thick.  This  oxide  melts  at  a  much  higher  temperature 
(5000  deg.  F.)  than  aluminum  (1215  deg.  F.)  and  as  the  oxide 
is  of  greater  specific  gravity  (heavier)  than  molten  aluminum, 
it  will  sink  down  into  the  metal  when  welding  unless  it  is  re- 
moved in  some  way.  As  the  oxide  is  very  persistant  to  the  action 
of  any  acid  or  alkali,  even  at  a  high  temperature,  any  flux  used 
must  of  necessity  be  drastic  in  action  and  if  carelessly  used, 
exceedingly  injurious  to  the  aluminum  weld.  On  this  account 
any  flux  should  be  used  with  caution  and  any  surplus  removed 
as  soon  as  possible. 

TABLE  XVII. — FLUXES  FOR  WELDING  ALUMINUM 

FORMULA  NUMBERS 

12  3456  7* 

CHEMICALS  ®/          07         GJ        o?         o?         o?        07 

Sodium  Chloride 30.        ...       12.5      16.       17.        6.5      30. 

Potassium  Chloride  45.       33.3      62.7       79.      83.       56.        45. 

Lithium  Chloride 15.       33.3      20.8      23.5      15. 

Sodium  Fluoride 33.3        

Potassium  Fluoride 7 ^. 

Sodium  Bisulphate 3 

Potassium  Bisulphate 4 3. 

Sodium  Sulphate 4. 

Potassium  Sulphate 5 

Aluminum  Sodium  Fluoride 10. 

*  Recommended  l)y  the  French  Laboratories  of  the  Autogenous  Weld- 
ing Association. 

A  flux  is  generally  used  in  welding  sheet  aluminum  where 
the  puddling  method  cannot  well  be  employed.  More  divergence 


WELDING  VARIOUS   METALS  AND  FLUXES  USED       175 

must  be  allowed  than  for  iron.  Fluxes  are  usually  composed  of 
alkaline  fluorides,  chorides  or  other  combinations  as  shown  in 
Table  XYII.  However,  these  and  other  flux  mixtures  are  only 
given  for  reference  purposes,  and  it  cannot  be  too  strongly 
urged  that  all  welders  buy  the  fluxes  used  and  follow  directions 
in  each  case. 

Where  a  flux  is  used  in  welding  aluminum,  the  edges  and 
adjacent  surfaces  should  be  well  scraped  and  cleaned  as  the 
flux  is  only  intended  to  eliminate  the  oxide  and  not  grease  and 
dirt.  In  welding  heavy  sheets  the  edges  should  be  beveled  and 
in  light  ones  the  welding  will  be  aided  by  flanging  the  edges 
about  Vie  in. 

Aluminum  castings  are  handled  a  little  differently  from 
sheets  or  plates.  As  previously  mentioned  castings  are  of  differ- 
ent composition.  Since  the  metal  has  a  low  melting  point,  high 
conductivity,  and  becomes  rather  fragile  previous  to  fusion, 
preheating  and  cooling  must  be  carried  out  very  carefully.  The 
average  aluminum  casting  is  somewhat  complicated  in  its  design, 
hence  the  necessity  of  skillfulness  in  carrying  it  through  the 
preliminary  heating  period. 

The  use  of  a  flux  on  aluminum  castings  has  been  abandoned 
by  the  majority  of  welders.  In  place  of  it  they  break  down 
and  remove  the  oxide  by  means  of  a  paddle,  which  is  also  used 
to  smooth  off  the  surface  of  the  weld  after  it  is  completed.  In 
many  cases  it  is  an  advantage  when  working  on  castings,  not  to 
bevel  the  edges. 

In  most  cases  aluminum  articles  should  be  preheated  to  some 
extent  before  welding.  In  certain  cases  the  playing  of  the 
secondary  flame  on  the  object  will  be  sufficient;  in  others  a 
more  thorough  treatment  is  required,  such  as  charcoal  or  coke. 
On  the  regular  run  of  castings  it  is  safest  to  preheat  to  about 
500  or  600  deg.  F.,  which  on  iron  would  correspond  to  a  low 
red  heat.  In  the  case  of  a  broken  lug  or  piece  of  a  flange,  it 
is  often  really  dangerous  to  preheat  as  it  may  cause  the  whole 
piece  to  collapse  or  distort.  The  beginner  should  also  be  very 
careful  about  shifting  or  turning  a  hot  aluminum  casting  as  it 
may  get  out  of  shape  or  crumble  into  pieces.  Since  the  metal 
is  so  apt  to  crumble  when  hot  it  is  advisable  for  the  beginner, 
and  often  the  expert,  to  back  up  the  parts.  This  may  be  done 
by  molding  a  backing  out  of  asbestos  fiber  2  parts  and  plaster 


176  GAS  TORCH  AND  THERMIT  WELDING 

of  paris  1  part,  made  into  a  thick  paste  with  water.  Have  this 
mold  about  an  inch  thick  and  perfectly  dry  before  setting  in 
place.  Fireclay  may  also  be  used  in  many  cases  to  back  up  or 
support  fragile  parts.  When  the  weld  is  completed  the  casting 
should  be  allowed  to  cool  very  slowly  and  evenly.  The  iron 
puddling  rod  should  not  be  allowed  to  get  too  hot  or  oxide  of 
iron  will  be  formed  and  scale  off,  making  a  defective  weld. 

Only  a  small  amount  of  metal  from  the  welding  rod  should 
be  added  at  a  time  and  this  must  be  thoroughly  stirred  or 
"puddled"  until  a  pool  is  formed  that  insures  perfect  fusion 
with  the  surrounding  parts.  Use  the  puddling  rod  to  scrape  off 
surplus  metal  while  it  is  in  a  pasty  condition.  The  beginner 
will  find  it  a  little  difficult  to  manipulate  the  puddling  and  the 
welding  rods  alternately  with  the  same  hand  but  this  becomes 
a  habit  with  practice,  and  many  do  this  by  holding  them 
between  the  fingers  so  that  neither  needs  to  be  laid  down.  The 
property  of  conducting  heat  is  greater  in  aluminum  than  in 
iron,  but  as  the  melting  point  is  much  lower,  about  the  same 
size  torch  tip  is  used  as  for  cast  iron  of  corresponding  thickness. 

Filling  a  Large  Hole. — The  Journal  of  Acetylene  Welding 
says  that  when  the  filling  of  a  large  hole  is  required  a  chill  of 
galvanized  iron  is  provided,  backing  up  the  hole  and  welding 
against  this  when  filling  the  hole  with  aluminum.  Galvanized 
iron  is  preferable  to  any  other  material,  such  as  tin  or  iron, 
since  it  peels  away  from  the  aluminum  quite  readily,  and  can 
therefore  be  easily  removed  after  the  weld  has  been  completed. 
This  is  undoubtedly  due  to  the  zinc  content  of  the  galvanizing 
composition. 

The  chief  value  of  the  use  of  the  chill  is  that  it  causes  the 
filler  to  cool  and  harden  quickly,  thereby  preventing  it  from 
contracting  after  the  weld  is  finished.  It  also  prevents  the 
heat  of  the  weld  from  spreading,  which  might  cause  the  job 
to  crack  back. 

The  chill  causes  the  added  metal  to  cool  almost  as  fast  as 
it  is  connected  to  the  edge  of  the  break.  After  the  weld  has 
been  finished  and  cooled,  the  chill  can  be  removed  by  gently 
prying  it  away  from  the  weld  by  means  of  a  cold  chisel. 

Brass  and  Bronze. — The  composition  of  brasses  and  bronzes 
varies  so  widely  that  it  is  not  good  for  a  welder  to  use  welding 
rods  of  the  same  composition  for  the  general  run  of  repair 


WELDING   VARIOUS   METALS   AND   FLUXES   USED       177 

work.  However,  rods  of  Tobin  bronze  or  manganese  bronze 
are  very  satisfactory  for  all-round  work.  Where  it  is  important 
to  match  the  color  of  the  weld  with  that  of  the  surrounding 
metal  it  is  necessary  to  use  special  rods  of  practically  the  same 
composition  as  the  welded  metal,  and  also  to  use  extra  care  with 
the  torch.  This  latter  will  be  better  understood  when  the  welder 
knows  that  several  of  the  alloys  such  as  zinc,  tin,  etc.,  used  with 
copper  to  make  brass  or  bronze,  volatilize  easily  and  in  so  doing 
change  the  character  of  the  metal.  These  metals  should  be 
prepared  in  the  same  way  as  any  otjier.  They  must  be  so 
placed  as  to  not  move  during  the  welding.  Fireclay  may  be 
used  to  back  up  pieces  in  danger  of  collapse.  The  end  of  the 
flame  cone  should  not  touch  the  metal,  but  should  be  kept  some 
distance  above  it.  If  a  white  smoke  rises,  or,  as  in  the  case  of 
bronze,  the  metal  bubbles,  remove  the  flame,  as  it  indicates  that 
too  much  heat  is  being  used  and  some  of  the  elements  are 
passing  off  in  vapor.  Do  not  breathe  this  vapor  as  it  is  poison- 
ous. It  is  desirable  to  use  a  tip  about  the  same  size  as  for  cast 
iron.  A  flux  should  be  used  though  not  too  liberally.  Calcined 
borax  is  good.  Boracic  acid  is  also  good  and,  if  used,  may  be 
applied  by  dipping  the  hot  rod  into  the  powder  from  time  to 
time.  The  principal  points  to  watch  are  not  to  heat  too  hot; 
do  not  move  the  parts  until  well  cooled ;  do  not  use  too  much  flux, 
and  be  sure  to  guard  against  caving  in  or  distortion  of  the 
work  by  properly  supporting  it  previous  to  heating.  If  the 
metal  is  porous  on  cooling  it  is  a  sure  sign  that  too  high  a  heat 
was  used. 

Cast  Iron. — When  cast  iron  is  molten  it  oxidizes  very 
rapidly.  The  oxide  which  begins  to  form  at  a  bright  red  heat, 
melts  at  a  temperature  of  2400  to  2450  deg.  F.  Since  the  metal 
itself  melts  at  a  temperature  several  hundred  degrees  below 
this,  ft  can  be  seen  that  the  oxide  will  not  be  melted  at  the 
same  time  as  the  metal.  In  order  to  break  the  oxide  down  and 
allow  the  metal  to  flow  together  a  flux  must  be  used.  A  properly 
formulated  flux  will  dissolve  the  oxide  and  float  it  to  the 
surface,  so  that  it  may  be  removed  by  scraping  the  molten 
surface  with  the  end  of  the  welding  rod.  The  welder  should 
tap  the  end  against  something  to  free  it  from  oxide  before  con- 
tinuing to  add  it  to  the  weld. 

A  good  flux  for  use  in  welding  cast  iron  may  be  made  up  of 


178  GAS  TORCH  AND  THERMIT  WELDING 

equal  parts  of  carbonate  of  soda  (washing  soda)  and  bicarbonate 
of  soda  (baking  soda).  There  is  practically.no  advantage  in 
using  the  pure  chemicals  in  this  case  as  the  commercial  product, 
which  may  be  obtained  at  the  grocery  store,  will  do  as  well  as 
any.  The  two  sodas  should  be  thoroughly  mixed,  however,  which 
may  be  done  by  running  them  through  an  old  coffee  mill  several 
times,  or  thoroughly  shaking  and  sifting  in  a  sieve.  The  flux 
is  applied,  as  in  most  other  cases,  by  dipping  the  hot  welding 
rod  into  it. 

Cast  iron  is  quite  fluid  when  melted.  For  this  reason  it 
offers  considerable  difficulty  where  vertical  or  overhead  welding 
is  attempted.  Also  its  fluidity  causes  it  to  entrap  gases,  dirt, 
and  oxide.  These  may  be  removed  by  proper  manipulation  of 
the  torch  and  welding  rod.  As  the  molten  iron  can  be  forced 
ahead  of  the  weld  very  easily,  adhesion  to  the  cold  metal  will 
result,  if  the  welding  is  not  watched  carefully. 

The  silicon  will  volatilize  to  some  extent  in  the  molten  metal 
and  the  lowering  of  the  amount  of  this  constituent  will  seriously 
increase  the  hardness  of  the  metal.  In  'order  to  compensate 
for  this  loss,  a  welding  rod  is  used  that  contains  from  2.75  per 
cent  to  3.5  per  cent  silicon.  The  other  substances  such  as  sulphur, 
manganese,  and  phosphorus  should  be  kept  within  rigid  limits. 
The  welding  rod  should  be  soundly  cast,  free  from  dirt,  sand, 
scale,  rust,  etc. 

The  welding  flame  should  always  be  neutral.  The  flame 
should  be  applied  to  the  weld  at  such  an  angle  that  the  metal 
will  not  be  blown  ahead.  Inasmuch  as  the  metal  is  quite  fluid 
when  molten,  the  welding  is  carried  on  in  a  series  of  overlapping 
"pools"  or  puddles.  The  welding  rod  is  applied  by  placing  it 
in  these  pools  and  playing  the  flame  around  it.  The  welding 
is  aided  by  continually  "working"  the  rod  in  the  weld  in  order 
that  blowholes,  dirt,  scale,  etc.,  will  be  forced  out. 

The  central  jet  of  the  flame  should  never  impinge  on  the 
molten  metal.  It  should  be  held  1/8  in.  to  3/1G  in.  from  it. 
Occasionally  it  is  necessary  to  remove  a  blowhole,  in  which 
case  the  hole  is  burnt  out  with  the  flame  and  then  the  metal 
is  worked  over  with  the  welding  rod.  The  working  over  of  a 
weld  should  be  avoided  unless  it  is  absolutely  necessary.  If  it 
is  necessary  to  do  this  the  welding  rod  should  be  used  always, 
for  otherwise  a  portion  of  the  silicon  will  be  lost. 


WELDING  VARIOUS   METALS  AND   FLUXES  USED       179 

When  the  weld  is  finished  and  it  is  still  hot,  the  accumula- 
tion of  scale,  dirt,  flux,  etc.,  011  the  surface  should  be  removed 
by  scraping  with  a  coarse  file  or  other  tool.  This  is  a  superficial 
coating  that,  when  cold,  is  very  hard. 

As  soft  welds  are  nearly  always  desired,  the  casting  should 
bo  cooled  slowly  and  evenly.  Where  the  work  is  complicated 
or  of  heavy  section,  it  is  by  all  means  best  to  reheat  it  to  a 
good  red  heat  and  then  allow  is  to  cool  slowly.  In  some  cases 
where  charcoal  has  been  used  it  is  sufficient  to  allow  the  casting 
to  cool  in  the  preheating  fire,  without  the  additional  reheating. 

Cast  Iron  to  Steel. — To  weld  cast  iron  to  steel,  cast-iron 
rods  must  be  used  as  the  welding  material.  The  steel  must  be 
heated  to  the  melting  point  first,  as  cast  iron  melts  at  a  lower 
temperature.  A  very  little  flux  should  be  used. 

Copper. — Copper  usually  is  produced  in  an  almost  pure 
homogeneous  form.  The  impurities  are  present  in  small  amounts 
and  are  not  affected  materially  by  fusion.  Copper  is  a  good 
conductor  of  heat,  and  is  very  tough,  ductile,  and  malleable. 

From  these  properties  it  would  appear  that  it  is  easily 
welded.  Unfortunately  this  is  not  true.  There  are  few  welders 
skilled  in  the  handling  of  this  metal. 

Copper  has  two  very  pronounced  properties  under  the  weld- 
ing flame.  It  absorbs  gases  very  readily,  notably  carbon  monoxide 
and  hydrogen.  These  are  released  when  the  metal  begins  to 
solidify,  with  the  result  that  they  remain  entrapped,  producing, 
a  porous  structure. 

Copper  oxidizes  very  rapidly  when  undergoing  fusion.  The 
molten  metal  has  the  property  of  dissolving  the  oxide  thus 
formed.  It  will  take  up  such  large  quantities  of  it  that  the 
mechanical  properties  of  the  weld  will  be  affected.  In  addition 
to  these  two  peculiarities  the  tensile  strength  of  copper  de- 
creases rapidly  as  the  temperature  is  raised,  particularly  from 
500  deg.  F.  upward.  The  effect  of  temperature  is  so  severe 
that  at  900  deg.  F.  the  tensile  strength  is  only  40  per  cent  of 
that  at  atmospheric  temperatures. 

Because  of  this  weakening  under  heat,  the  strains  resulting 
from  contraction  in  the  weld  during  cooling  must  be  carefully 
dissipated,  otherwise  the  metal  in  the  weld  or  adjacent  to  it 
will  fail. 

A  neutral  flame  should  always  be  applied  in  welding  this 


180  GAS  TORCH  AND  THERMIT  WELDING 

metal.  If  an  excess  of  acetylene  is  used  the  products  of  com- 
bustion are  richer  in  those  gases  which  are  easily  absorbed.  If 
an  oxidizing  flame  is  used,  the  weld  becomes  saturated  with  the 
oxide. 

A  larger  size  torch  tip  than  the  melting  point  of  copper  in- 
dicates is  used  because  of  the  high  thermal  conductivity.  Where 
possible,  auxiliary  heating,  such  as  air-gas  flames  and  charcoal 
fires,  should  be  employed.  This  is  done  not  only  from  the 
standpoint  of  economy,  but  it  also  aids  greatly  in  the  success 
of  the  weld. 

The  torch  flame  should  play  on  the  weld  in  a  vertical  direc- 
tion. The  metal  when  molten  is  quite  fluid,  and  for  this  reason 
if  the  torch  were  applied  at  an  angle  the  metal  would  be  blown 
ahead,  producing  adhesion.  Also,  by  applying  the  torch 
vertically  the  molten  metal  is  protected  from  the  oxygen  of  the 
atmosphere  by  means  of  the  enveloping  flame. 

Copper,  if  properly  prepared  and  free  from  grease  or  dirt, 
does  not  need  a  flux. 

The  factor  that  contributes  most  to  the  successful  welding 
of  copper  is  the  use  of  a  properly  formulated  welding  rod.  Such 
a  rod  will  overcome,  to  a  great  extent,  both  the  absorption  of 
gases  and  the  solution  of  the  oxide.  It  is  not  considered  prac- 
tical to  remove  the  oxide  in  the  weld  by  means  of  a  flux,  because 
it  is  dissolved  in  the  metal.  A  welding  rod  is  needed  that  has 
combined  with  it  a  reducing  or  deoxidizing  agent.  The  reducing 
agent  has  a  greater  affinity  for  oxygen  than  copper,  hence  it 
combines  with  it  and  brings  it  to  the  surface  in  a  fluid  form. 
This  material  acts  as  a  glaze  or  protecting  coating  for  the  molten 
metal  beneath  it,  with  the  result  that  it  tends  to  retard  the 
absorption  of  the  gases. 

Several  materials,  when  added  to  a  pure  copper  rod,  have 
proved  to  be  beneficial.  The  most  prominent  element  at  this 
time  is  phosphorus.  It  should  be  present  in  amounts  not  over 
1.0  per  cent;  otherwise  the  metal  will  be  pasty  and  the  weld 
will  be  weakened. 

Newly  welded  copper  has  only  the  strength  of  cast  copper, 
but  after  welding,  the  grain  of  the  weld  and  the  metal  adjacent 
can  be  improved  by  hammering  at  a  low  heat. 

Copper  to  Steel. — If  it  is  desired  to  weld  copper  to  steel, 
heat  the  steel  to  a  welding  heat,  then  place  the  copper  in  con- 


WELDING  VARIOUS   METALS  AND   FLUXES  USED       181 

tact.  The  metals  will  then  fuse  together.  Take  away  the  flame 
as  soon  as  the  copper  flows  properly.  No  flux  is  needed. 

Lead. — Lead  can  be  readily  welded.  The  process,  how- 
ever, is  usually  known  as  "lead  burning."  The  gas  torch  pro- 
vides a  means  of  doing  this  work  quickly  and  at  a  low  cost. 
Skill  in  the  manipulation  of  the  torch  is  necessary,  particularly 
on  vertical  seams.  A  light  torch  should  be  used.  When  welding 
sheets  or  plates,  proceed  as  in  lead  burning  by  other  processes. 

The  burned  joint  on  a  lead  or  block  tin  pipe  line  is  not 
only  a  neat  and  permanent  joint,  but  is  all  lead,  and  a  block 
tin  line  is  all  block  tin.  The  joints  are  fused  together  with  the 
addition  of  enough  metal  of  the  same  kind.  If,  for  instance,  a 
lead  pipe  line  is  to  carry  acid,  the  burned  joints  contain  no 
solder  which  could  be  attacked  by  the  acid. 

In  preparing  lead  pipe  for  welding  the  two  pipe  ends  are 
scraped  clean  for  about  an  inch  back,  and  are  tapered  slightly 
at  the  edges.  It  is  not  necessary  to  drive  one  pipe  into  the 
other.  The  two  ends  are  merely  placed  in  contact  and  welded 
or  "burned"  with  the  addition  of  more  lead  to  fill  up  the  joint. 
No  flux,  no  grease  and  no  "wiping"  of  any  kind  is  needed. 

Malleable  Iron. — The  manufacture  of  malleable  iron  has 
made  enormous  progress  during  the  last  few  years,  and  while 
formerly  malleable  iron  was  really  an  unknown  quantity  and 
might  contain  different  mixtures,  from  white  iron  to  hard  steel, 
in  the  same  casting,  a  great  uniformity  is  now  obtainable  by 
adherence  to  strictly  scientific  methods. 

The  Associated  Manufacturers  of  Malleable  Iron  has  set  a 
standard  of  quality,  to  which  all  its  members  must  adhere  rigidly 
and  castings  procured  from  one  of  its  members  may  be  relied 
on  to  consist  of  a  uniform  and  thoroughly  high-class  product. 

While  formerly  the  welding  of  malleable  iron  was  considered 
almost  impracticable  on  account  of  the  different  structures  in  one 
and  the  same  casting,  it  may  now  be  welded  with  almost  a  cer- 
tainty of  success,  if  the  casting  was  made  in  accordance  with  the 
rules  of  the  association. 

The  break  on  malleable  iron  is  prepared  exactly  the  same 
as  for  any  welding  job,  cleanliness  in  this  instance  being  espe- 
cially desirable,  since  dirt  tends  to  weaken  the  weld  considerably. 
Allowance  should  be  made  for  the  effects  of  expansion  and  con- 
traction; malleable  iron  is  less  liable  to  break  than  cast  iron, 


182  GAS  TORCH  AND  THERMIT  WELDING 

since  it  is  ductile,  but  will  be  distorted  unless  such  provisions 
are  made.  Use  for  flux  the  same  powder  used  for  brass — that 
is :  borax  or  a  purchased  mixture. 

As  with  cast  iron,  do  not  let  the  end  of  the  cone  touch  the 
casting,  but  hold  it  just  a  little  distance  away.  Watch  the  metal 
carefully  and  as  soon  as  the  metal  begins  to  melt,  add  the  filling 
rod,  either  Norway  iron  or  malleable  rod  of  the  same  grade  as 
the  casting. 

However,  not  all  malleable  castings  are  of  the  high  degree 
just  described.  They  were  originally  white  cast  iron,  very  brittle 
and  hard.  By  heat-treatment  the  carbon  content  is  changed, 
and  instead  of  the  brittle  casting,  it  becomes  ductile,  fairly 
soft  and  changes  to  a  darker  color.  Just  how  far  into  the  body 
of  the  metal  this  change  penetrates  depends  upon  the  size  of 
the  casting  and  the  length  of  the  heat-treatment,  so  that  a  malle- 
able casting,  as  it  is  generally  called,  may  be  steel  on  the  surface, 
a  semi-steel  part'  way  through  and  white  cast  iron  at  the  core. 

Very  small  castings  sometimes  are  steel  all  the  way  through 
and  we  may  weld  them  without  flux,  using  Norway  iron  or 
mild  steel  as  the  welding  rod. 

In  nearly  all  cases,  however,  it  will  be  found  that  the  casting, 
if  not  made  to  association  specifications,  is  composed  of  different 
metals — if  the  break  is  examined,  we  can  tell  this  by  the  differ- 
ent colors.  It  is  obvious  that  such  a  casting  cannot  be  welded, 
since  it  would  be  extremely  difficult  to  determine  just  where 
one  metal  left  off  and  another  began.  The  practice  of  using 
cast  iron  as  a  welding  rod  on  malleable  castings  is  not  a  good 
one,  since  the  bond  is  very  brittle  and  in  all  cases  where  strength 
is  desired  we  would  better  use  manganese  or  Tobin  bronze — 
in  this  way  securing  a  brazed  joint  instead  of  a  welded  one, 
of  a  different  color  than  the  casting  but  with  the  factor  of 
strength  a  big  one. 

Watch  the  metal  carefully  and  when  the  spot  the  flame  is 
playing  upon  reaches  a  bright  red  heat,  bring  the  bronze  welding 
rod,  which  has  previously  picked  up  some  borax,  down  upon 
this  section,  being  careful  that  the  cone  does  not  come  directly 
in  contact  with  the  bronze  rod.  Bronze  melts  at  a  lower  tem- 
perature than  malleable  iron  and  with  the  iron  at  a  bright  red 
heat,  and  with  plenty  of  flux  used,  it  will  be  found  that  the 
bronze  attaches  itself  to  the  iron.  We  must  not,  however  melt 


WELDING  VARIOUS   METALS  AND  FLUXES  USED       183 

any  portion  of  the  malleable  iron  and  we  must  not  play  the 
cone  directly  on  the  iron  or  on  the  bronze. 

Monel  Metal. — Technically,  monel  metal  is  an  alloy  of  nickel 
and  copper,  containing  about  67  per  cent  nickel,  28  per  cent 
copper,  and  5  per  cent  of  other  elements.  This  remaining  5 
per  cent  consists  partly  of  iron  from  the  original  ore  and  partly 
of  manganese,  silicon,  and  carbon  introduced  in  the  process  of 
refining.  It  contains  no  zinc  or  aluminum.  The  alloy  can  be 
machined,  forged,  soldered  and  welded,  both  electrically  and  by 
the  gas  torch.  In  the  automobile  industry  it  is  used  for  float 
valves  in  carburetors  because  it  combines  hardness  with  non- 
corrodibility.  Borax  or  boracic  acid  may  be  used  as  a  flux. 

Nickel. — Nickel  melts  at  2600  deg.  F.  and  when  melted  has 
the  property  of  absorbing  large  amounts  of  various  gases,  espe- 
cially oxygen.  The  gases  so  absorbed  remain  when  the  metal 
cools,  making  it  very  porous.  Nickel  has  also  a  great  affinity 
for  sulphur.  It  is  often  stated  that  nickel  cannot  be  welded, 
but  this  is  an  error,  although  it  is  an  extremely  difficult  metal 
to  weld  satisfactorily.  Anodes  used  in  nickel  plating  may  be 
fused  together  without  flux  as  the  blowholes  do  not  affect  the 
conductivity  to  any  appreciable  extent.  However,  where  a  weld 
is  wanted  free  from  blowholes,  the  nickel  pieces  should  be  laid 
on  a  heavy  plate  heated  bright  red  or  white,  and  the  nickel 
heated  to  a  bright  white  with  the  gas  torch.  The  joint  should 
then  be  carefully  hammered  with  a  light  hammer.  Previous  to 
heating  the  nickel  should  be  freed  from  grease  or  oil  and  scraped 
well  back  from  the  weld. 

Steel. — Steel  welding  on  a  commercial  scale  should  never 
be  attempted  until  after  the  operator  has  proved  to  his  own 
satisfaction  that  the  weld  is  strong  by  welding  together  mild 
steel  plates  ^  to  ^  in.,  sawing  them  through  the  weld  to  make 
sure  that  the  material  is  really  bonded  and  testing  them  by 
bending  back  and  forth  in  a  vise. 

Steel  melts  at  2500  to  2700  deg.  F.  When  molten  it  is  not 
extremely  fluid.  At  dull  red  heat  it  begins  to  oxidize  rapidly. 
The  oxide,  which  melts  at  a  temperature  of  several  hundred 
degrees  below  that  of  the  metal,  remains  at  the  surface  and 
can  be  easily  removed.  A  flux  is  not  necessary,  although  some 
welders  use  a  little  borax.  Close  attention  must  be  paid  to  the 
removal  of  the  oxide,  however,  for  its  presence  is  very  harmful. 


184  GAS  TORCH  AND  THERMIT  WELDING 

It  is  a  common  fault  to  have  layers  of  oxide  in  the  weld,  which 
cause  a  laminated  structure  that  weakens  it. 

Steel  does  not  melt  rapidly.  It  gradually  comes  to  fusion, 
confined  to.  small  areas.  Because  of  this,  the  weld  is  made  up 
of  small  overlapping  layers.  The  strength  of  the  weld  depends 
greatly  on  the  thorough  bonding  of  these  layers  to  each  other 
and  to  the  beveled  edges  of  the  piece  being  welded.  It  is  a 
common  fault  to  force  the  metal  ahead  of  the  welding  area  and 
allow  it  to  adhere  to  the  cold  sides  of  the  beveled  edges. 

A  welding  rod  of  over  99  per  cent  pure  iron  wire  is  com- 
monly used.  Occasionally  a  nickel  steel  rod  is  used  with  good 
results  on  such  work  as  crankshafts.  A  mild-steel  rod  is  par- 
ticularly satisfactory  on  steel  castings. 

Diameter  of 
Thickness  of  Steel  Welding  Rod 

1/8  in 1/16  in. 

1/4  in.  to  3/16  in 1/8  in. 

1/4  in.  to  3/8  in 3/16  in. 

1/2  in.  and  up 1/4  in. 

Steel  is  very  sensitive  to  the  welding  flame.  An  excess  of 
acetylene  tends  to  carbonize  the  metal;  an  excess  of  oxygen 
tends  to  oxidize.  Therefore,  a  neutral  flame  should  always  be 
used  and  should  be  tested  frequently  in  order  that  it  be  kept 
in  proper  adjustment. 

Failures  due  to  expansion  and  contraction  are  not  numerous, 
because  of  the  toughness  and  strength  of  the  metal.  If  expan- 
sion and  contraction  are  not  properly  taken  care  of,  however, 
warping  and  buckling  will  surely  take  place,  and  internal  strains 
will  exist  in  the  weld. 

These  can  be  avoided  by  properly  setting  up  the  work  and 
with  proper  preheating  methods. 

The  strength  of  a  steel  weld  can  be  improved  by  mechanical 
treatment.  Hammering  is  the  most  common  method  employed. 
After  the  welding  has  been  completed,  the  entire  weld  should 
be  heated  to  a  bright  red  heat,  and  the  hammering  carried  on 
at  this  temperature.  If  the  hammering  is  done  at  a  lower 
temperature,  the  weld  will  be  weakened  instead  of  strengthened. 

The  welder  should  always  keep  in  mind  that  the  higher  the 
percentage  of  carbon  in  the  steel  the  greater  is  the  danger  of 
burning  the  metal,  with  its  consequent  weakening  effect. 


WELDING  VARIOUS   METALS  AND  FLUXES   USED       185 

Steel  castings  should  be  handled  in  a  manner  similar  to  cast 
iron.  They  may  be  preheated  and  prepared  in  the  same  way. 
Cast  steel  as  a  rule  has  a  percentage  of  carbon  between  that  in 
mild  steel  and  gray  cast  iron.  As  a  filler,  good  results  will  be 
obtained  if  cast  bars  of  the  same  material  are  used.  If  not 
available,  use  vanadium  steel  or  Norway  iron  filler. 

While  little  work  is  done  in  welding  high  carbon  or  hard 
steel,  the  following  instructions  are  given  as  a  guide  to  the 
operator  in  case  of  necessity.  Parts  should  be  prepared  for 
welding  as  for  wrought  iron  or  steel.  Use  a  larger  tip  than  for 
the  same  thickness  of  mild  steel.  For  filling  material  where  the 
parts  are  to  be  hardened,  use  ordinary  drill  rod.  Drill  rod  is 
a  hard  steel  which  is  used  by  tool  manufacturers  in  the  manu- 
facture of  drills,  reamers,  etc.  Ordinary  mild  steel  cannot  be 
tempered  and  this  is  often  necessary  when  high  carbon  or  hard 
steel  parts  have  to  be  welded.  Employ  cast-iron  flux.  Execute 
the  weld  very  rapidly  as  there  is  a  tendency  for  the  metal  to 
burn  easily  and  also  to  decarbonize;  that  is,  to  burn  out  the 
carbon,  leaving  the  metal  in  poor  condition.  A  very  slight 
excess  of  acetylene  in  the  welding  flame  may  be  advantageous. 

To  weld  high-speed  steel  to  ordinary  machine  steel,  the  end 
of  the  high-speed  steel  to  be  welded  must  first  be  heavily  coated 
with  soft  special  iron.  It  can  then  be  welded  to  ordinary 
machine  steel  without  burning,  but  it  takes  an  experienced 
welder  to  make  a  good  weld  of  this  kind. 

Special  Steels. — There  are  many  special  or  alloy  steels  used 
in  the  metal  industry.  The  operator  is  often  called  upon  to 
attempt  welding  on  these.  Many  automobile  and  locomotive 
parts  are  made  from  special  high-carbon  steels,  and  often  these 
castings  or  forgings  undergo,  during  manufacture,  special  heat- 
treatments  which  are  in  many  cases  more  or  less  of  a  secret 
process.  It  will  be  appreciated  that  welding  with  a  high-tem- 
perature flame  must  necessarily  counteract  the  effects  that  were 
produced  by  the  heat-treatments,  consequently,  to  make  the 
part  efficient  it  is  essential  that  after  welding,  the  piece  be 
properly  heat-treated  by  an  operator  skilled  in  such  work.  The 
services  of  such  a  man  are  rarely  available,  therefore,  the  results 
obtained  when  welding  high-carbon  alloy  steels  will  be  uncertain. 
Fortunately,  however,  many  of  the  alloy  steels  used  in  practice 
are  not  high  carbon  and  can  be  welded  satisfactorily. 


186  GAS   TORCH  AND   THERMIT   WELDING 

Manganese  Steel  (low  carbon)  is  welded  quite  readily. 
The  manganese  acts  as  a  deoxidizing  agent ;  that  is,  it  counteracts 
the  effect  of  burning  the  metal.  If  possible,  use  a  filling  mate- 
rial of  the  same  composition  as  the  part  welded.  If  this  cannot 
be  obtained  use  Norway  iron. 

Nickel  Steel  (low  carbon)  can  be  welded  without  difficulty 
in  exactly  the  same  way  as  mild  steel,  but  nickel-steel  filling 
rod  must  be  used. 

Vanadium  Steel  (low  carbon) — This  is  probably  the  most 
commonly  used  steel  alloy.  Very  fortunately  it  is  extremely 
easy  to  weld,  and  flows  much  more  readily  than  ordinary  mild 
steel.  Weld  as  mild  steel,  but  use  vanadium-steel  filler. 

Chrome  Steel  is  in  the  class  of  mild  or  low-carbon  steel 
and  can  be  welded  readily.  Weld  as  mild  steel.  Use  a  chrome- 
steel  filler.  Many  chrome  steels,  however,  are  in  the  high-carbon 
or  hard-steel  class. 

Wrought  Iron  may  be  easily  welded  without  a  flux  though 
a  little  borax  or  other  flux  is  sometimes  advisable.  The  same 
general  rules  apply  as  for  mild  steel. 

Galvanized  Iron  cannot  be  welded,  since  the  iron  is  covered 
with,  and  to  a  greater  or  less  extent  impregnated  with,  a  lower 
melting  metal. 

German  Silver,  in  many  cases,  is  considered  unweldable, 
due  to  its  absorption  of  gases.  For  practically  all  commercial 
purposes,  it  may  be  bonded,  using  the  same  flux  as  for  brass 
and  a  strip  of  German  silver  for  the  welding  rod.  Especial 
care  must  be  given  to  expansion  and  contraction. 

White  Metal  Castings  used  for  die  molded  purposes  usually 
are  composed  of  aluminum,  tin  and  zinc  in  varying  proportions, 
but  nearly  always  with  the  lower  melting  metals  in  the  larger 
proportion.  While  the  castings  have  a  good  deal  the  same  ap- 
pearance as  aluminum,  they  are  considerably  heavier.  They  may 
be  considered  unweldable. 

Silver  acts  very  similar  to  nickel  and  should  be  welded  in 
the  same  way  by  heating  and  hammering.  However,  soldering 
usually  answers  all  purposes. 

Gold  welds  very  easily  and  the  pure  melting  process  is  all 
that  is  needed. 


CHAPTER  XII 
EXAMPLES  OF  WELDING  JOBS 

The  way  a  crack  to  be  welded  is  V'd  out  or  plates  are 
beveled,  has  already  been  outlined,  but  it  will  be  well  to  elaborate 
a  little  on  the  methods  of  doing  this  work.  On  steel  or  wrought 
iron,  the  beveling  may  be  done  with  a  gas  cutting  torch.  On 


FIG.  129.^ — An  Air  Chisel  May  be  Used  Either  for  Grooving  or  Finishing. 

other  metals,  such  as  aluminum  or  cast  iron,  the  gas  cutting 
torch  cannot  be  used,  although  the  metal  may  be  roughly  melted 
away.  Sometimes  the  work  is  of  such  a  nature  that  the  bevel 
may  be  ground,  either  with  a  stationary  or  a  portable  electric 
grinding  machine.  On  cast  iron,  a  sledge  and  a  handled  chisel 
is  often  the  cheapest  and  quickest  way,  and  in  nearly  every 
case  it  is  superior  to  melting  the  metal  away  with  a  gas  torch. 
A  very  satisfactory  beveling  tool  for  all-round  shop  work, 
is  an  electric  or  a  pneumatic  chisel  such  as  shown  in  use  in 
Fig.  129.  This  may  also  be  used  for  taking  off  surplus  metal 
after  welding,  although  a  portable  electric  grinding  machine  is 
usually  preferable. 

187 


188 


GAS  TORCH  AND  THERMIT  WELDING 


On  work  like  the  propeller  blade  shown  in  Fig.  130,  the 
slots  may  be  cut  with  a  saw  or  a  milling  cutter  and  the  pieces 


FIG.  130.— Propeller  Blade  Partly  Beveled  for  Welding. 


FIG.  131. — Cylinder  Grooved  Out  for  Welding. 

left  may  be  knocked  off  with  a  hammer.  This  bevel  might  also 
be  chipped,  ground  or  melted  off,  as  the  occasion  or  equipment 
at  hand  demanded  or  made  advisable. 


EXAMPLES  OF  WELDING  JOBS 


189 


An  engine  cylinder  grooved  out  and  ready  for  preheating 
is  shown  in  Fig.  131.    In  a  case  of  this  kind  the  grooving  may 


FlG.  132. — The  Cylinder  as  Welded. 


FlG.  133. — Broken  Automobile  Cylinder. 

probably  be  best  done  by  using  a  sledge  and  handled  chisel 
for  the  easily  reached  parts,  and  a  pneumatic  chisel  for  the 


190 


GAS  TORCH  AND  THERMIT  WELDING 


rest.  However,  this  largely  depends  on  the  size  of  the  work 
and  the  judgment  of  the  workman.  Fig.  132  shows  the  cylinder 
welded  and  ready  to  be  smoothed  up. 

A  badly  broken  four-cylinder  block  is  shown  in  Fig.  133 
and  the  repair  in  Fig.  134.  The  actual  cost  to  weld  this  job 
was  less  than  five  dollars.  The  method  of  procedure  has  been 
previously  described. 

In  Fig.  135  a  welder  is  shown  working  on  a  job  while  a  helper 
is  tending  to  the  preheating  of  another.  The  method  of  weld- 
ing through  a  hole  in  a  large  sheet  of  asbestos  not  only  keeps 
the  heat  in,  but  protects  the  operator  as  well. 

In  Fig.  136  is  shown  a  badly  broken  aluminum  upper  crank 


FIG.  134.— The  Finished  Weld. 

case  and  the  repair.  Work  of  this  kind  often  comes  to  the 
shop  that  caters  to  the  automobile  trade.  Another  repair  of 
interest  to  the  garage  man  is  shown  in  Fig.  137.  The  cost  of 
putting  in  a  new  frame  in  this  5-ton  truck  would  have  been  at 
least  $600.  The  weld  was  finished  and  guaranteed  for  $25. 

The  welding  of  a  tire  for  a  15-ton  truck  wheel,  10  in.  wide 
by  2|  in.  thick,  is  shown  in  Fig.  138.  The  preheating  was  done 
in  a  large  blacksmith's  forge.  In  this  connection,  the  welder 
must  get  out  of  his  head  a  very  common  idea  that  preheating  is 
only  needed  to  take  care  of  expansion  and  contraction.  It  is 
just  as  valuable  in  its  way,  for  saving  expensive  welding  gas. 
This  is  the  reason  for  preheating  the  large  tire,  since  its  shape 
and  nature  precludes  any  expansion  of  contraction  troubles 
provided  the  welder  has  even  ordinary  skill. 


EXAMPLES  OF  WELDING  JOBS 


191 


FIG.  135. — Welding  and  Preheating. 


FIG.  136. — Broken  and  Repaired  Aluminum  Crank  Case. 


192 


GAS  TORCH  AND  THERMIT  WELDING 


In  the  example  shown  in  Fig.  139,  which  is  a  kettle  5  ft. 
6  in.  in  diameter  and  1J  in.  thick,  preheating  is  absolutely 
necessary  in  order  to  take  care  of  the  expansion  and  contraction. 
The  crack  was  around  the  outlet  and  was  22  in.  long.  The 


FIG.  137. — Welding  Frame  of  5-Ton  Motor  Truck. 


FIG.  138.-  Preheating  and  Welding  Large  Truck  Tire. 

welding  time  was  1  hr.  45  min.,  in  addition  to  the  time  it  took 
to  preheat  the  kettle  the  required  amount. 

The  welding  of  a  7-in.  crankshaft  for  a  200-hp.  internal- 
combustion  engine  is  shown  in  Fig.  140.  The  finished  weld  is 
shown  in  the  insert.  The  work  was  finished  and  the  crankshaft 
put  back  in  service  inside  of  30  hr.  The  section  of  the  shaft 
added  was  oversize  to  permit  machining  for  alignment.  Pre- 


EXAMPLES  OF  WELDING  JOBS 


193 


heating  in  this  case  saved  a  considerable  amount  of  welding  gas. 
The  improvised  furnace  also  made  slow  cooling  possible. 


FIG.  139. — Preheating  and  Welding  a  Large  Kettle. 


FIG.  140 Welding  a  Large  Crankshaft. 

Welding  Broken  Machine  Tools. — The  planing-machine  bed, 
shown  in  Fig.  141,  was  cracked  through  on  one  side  close  to  the 
housing  boss.  The  job  was  finished  without  serious  disalign- 


194 


GAS  TORCH  AND  THERMIT  WELDING 


ment,  but  under  ordinary  circumstances  such  a  repair  would  not 
be  recommended  unless  means  were  at  hand  for  rennishing  the 
ways  and  possibly  other  machined  surfaces.  As  a  war-emergency 


FIG.  141. — Weld  on  Large  Planing-Machine  Bed. 


PIG.  142.— Broken  Punch-Press  Frame. 

repair,  however,  it  proved  satisfactory.  The  redemption  of  a 
similar  casting,  damaged  while  still  in  the  rough,  might  also 
be  a  money-saving  proposition  in  some  cases. 

The  punch-press  frame  shown  in  Fig.  142,  outside  of  its 


EXAMPLES  OF  WELDING  JOBS  195 


FIG.  143. — Welded  Blowholes  in  Lathe  Pan. 


FIG.  144. — Welded  Crack  in  Lathe  Bed. 


FIG.  145.— Broken  Press  Frame  with  Breaks  Beveled. 


196  GAS  TORCH  AND  THERMIT  WELDING 


,^ 


J 


Fro.  146.— The  Welded  Press  Frame. 


FIG.  147. — Another  Welded  Press  Frame. 


EXAMPLES  OF  WELDING  JOBS  197 

size,  does  not  offer  any  serious  welding  difficulties,  as  any  possible 
distortion  can  be  taken  care  of  by  subsequent  adjustment.  The 
\velds  made  in  this  particular  case  were  12  in.  in  thickness, 
and  the  total  time  taken  to  get  the  press  back  in  service  was 
38  hr. 

The  saving  of  defective  castings  may  often  prove  a  very  im- 


FIG.  148. — Welding  Teeth  in  a  Large  Gear. 

port  ant  item  to  the  shop  management.  In  Fig.  143  is  shown 
a  lathe  bed,  weighing  900  lb.,  which  came  from  the  foundry 
with  sand  holes  in  the  pan.  These  were  easily  filled  up. 

Another  lathe  bed,  sand-cracked  where  the  bed  leg  joined  the 
pan,  is  shown  in  Fig.  144.  The  casting  weighed  1750  lb.  and 
was  saved  from  being  scrapped  by  27  min.  of  welding  work. 

A  broken  frame  of  a  punch  press  is  shown  in  Fig.   145. 


198 


GAS  TORCH  AND  THERMIT  WELDING 


This  frame  was  4J  ft.  high,  2J  ft.  wide  and  from  f  to  1J  in. 
thick.  It  weighed  500  Ib.  The  welder's  time  on  the  work  was  8J 
hr. ;  helper's  time,  8J. ;  oxygen  used,  425  cu.f t. ;  acetylene  used, 
327  cu.ft. ;  cast-iron  filler,  4  Ib. ;  preheating,  4  hr.  with  gas  at 
a  cost  of  60  cents.  The  total  cost  to-day  can  be  computed  by 
taking  the  present  cost  of  labor  and  supplies  and  multiplying 


FIG.  149. — A  Large  Pulley -Welded  in  Twelve  Places. 

by  the  figures  given.  The  finished  job  is  shown  in  Fig.  146. 
An  Oxweld  torch  was  used. 

A  much  simpler,  and  in  fact  almost  an  ideal  piece  to  weld, 
is  shown  in  Fig.  147.  The  frame  is  12  X  12  in.  at  the  break. 

Ten  teeth  were  broken  out  of  the  gear  shown  in  Fig.  148. 
The  gear  was  8  ft.  in  diameter  and  the  teeth  10  in.  long,  3  in. 
high  and  3  in.  thick.  It  is  seldom  necessary  to  preheat  in  a 
case  of  this  kind  except  to  save  gas,  but  care  should  be  taken  to 
keep  the  heat  in  as  much  as  possible. 


EXAMPLES  OF  WELDING  JOBS  199 

A  practical  man  would  at  once  question  the  advisability  of 
trying  to  repair  a  pulley  broken  as  indicated  in  Fig.  149,  This 
pulley  is  7  ft.  in  diameter  and  was  completely  welded  in  12 
places  as  indicated,  and  ready  for  service  in  48  hr.  The  work 
was  done  so  well  that  the  rim  ran  practically  true,  except  for 
about  J-in.  side  play.  This  particular  case  was  a  war-emergency 
job,  but  sometimes  such  a  repair  job  is  of  vital  importance  at 


FIG.  150. — A  \Velded  Locomotive  Frame. 

the  present  time,  for  such  a  pulley  can  seldom  be  replaced  by 
a  new  one  without  considerable  delay. 

In  many  instances  broken  locomotive  frames  may  be  quickly 
repaired  with  the  gas  torch  without  dismantling,  and  the  engine 
put  back  into  service  in  a  short  time.  Such  a  repair  is  shown 
in  Fig.  150.  This  job  took  altogether  less  than  24  hr.  from 
the  time  the  engine  was  run  in  until  it  was  on  the  road  again. 


200 


GAS  TORCH  AND  THERMIT  WELDING 


PREPARATION  FOR  LOCOMOTIVE  FRAME  WELDING 

Writing  in  the  Welding  Engineer,  G.  M.  Calmbach,  super- 
intendent of  welding  for  The  K.  C.  Southern  Railway,  gives 
directions  for  the  preparation  of  a  locomotive  frame  for 
welding. 

"Tram  frame  and  check  with  opposite  slide,  then  tram  over 
break  locating  permanent  points  by  which  the  expansion  will 
be  governed.  See  Fig.  151  for  expansion. 


LINE  UP  FRAME  AND  TGAM 
BEFORE  CUTTING  AWAV 
THEN  EXPAND  AS  SHOWN 

BY    "A  "—"&  • 


"ore-. 

AT  BREAKS  MARKED  A 
Alt&W  %'Ptto.  CONTRACTION 

AT  THOSE  MARKED  'B' 
AUOW  3//6' 


"  f 


FIG.  151.  —  Locomotive  Frame  Welding. 

"Frame  should  be  cut  out  from  both  sides  as  shown,  then 
surface  to  be  chipped  absolutely  clean  preparatory  to  welding. 

"Weight  of  engine  should  be  taken  off  of  frame  and  jacks 
placed  under  legs  of  jaws  on  either  side  of  weld. 

"Where  welds  are  to  be  made  in  any  part  of  jaw  binder 
should  be  in  place  if  possible. 

"As  an  expedient  to  start  the  weld  f-in.  plate  should  be 
tacked  to  lower  side  of  frame  on  which  a  foundation  can  be  made 
to  start  the  weld,  welding  plate  solid  to  frame  and  also  welding 
edges  of  plate,  this  plate  to  extend  out  on  both  sides  of  frame 
the  thickness  of  reinforce. 

"Two  operators  should  be  always  employed,  that  is,  one  on 
each  side  of  frame.  After  weld  reaches  the  thickness  of  2  in. 


EXAMPLES   OF  WELDING   JOBS 


201 


it  should  be  hammered,  this  hammering  to  continue  until  weld 
is  finished. 

"It  is  important  that  at  no  time  during  progress  of  weld  that 
any  part  of  weld  be  less  than  a  red  heat,  that  is  to  say,  operators 
should  keep  finished  part  of  weld  red  hot  at  all  times  and 
when  weld  is  finished,  the  entire  weld  should  be  brought  up  to 
?n  even  heat  before  jacks  are  removed. " 

The  gas  torch  is  almost  as  useful  for  welding  around  a 
shipyard  as  it  is  in  a  railroad  shop.  Fig.  152  shows  a  4-ton 
forged-steel  rudder  frame  broken  as  indicated  by  the  arrows. 


F 


FlG.  152. — Eudder  Frame  Ready  for  Welding. 

The  break  has  already  been  beveled  out  for  welding.  The  cost 
was  about  $60  as  compared  with  about  $1400  for  a  new  frame, 
and  the  time  taken  was  a  fraction  of  what  would  have  been 
required  to  obtain  a  new  one. 

COOLING  DEVICES 

On  many  large  jobs,  where  considerable  preheating  has  to 
be  done,  the  discomfort  of  the  welder  may  cause  defective  welds 
or  even  complete  failure.  Sometimes  asbestos  screens  can  be 
used;  at  other  times  it  is  necessary  to  shift  welders  every  few 
minutes.  Two  suggestions  that  may  be  helpful  in  certain  cases 
are  here  given.  H.  Howard  suggests  the  use  of  an  "air  screen " 
as  outlined  in  Fig.  153.  A  row  of  small  holes  is  drilled  in 


202 


GAS  TORCH  AND  THERMIT  WELDING 


a  pipe  of  convenient  size  to  attach  to  the  air  hose.  The  other 
end  of  the  pipe  is  closed.  This  .contrivance  is  placed  across 
under  the  torch  and  held  by  a  clamp  or  a  weight  in  such  a 
position  that  a  curtain  of  swiftly  moving  air  passes  between 
the  hot  casting  and  the  operator.  The  device  affords  protec- 
tion from  the  heat  and  does  not  interfere  with  the  manipulation 
of  the  torch  or  obstruct  the  view  of  the  operator. 


FIG.  153.— Cooler  for  Use  in  Welding. 

Acetylene- 


FIG.  154. — Another  Cooling  Device. 

This  device,  while  useful  for  certain  jobs,  has  disadvantages, 
as  it  does  not  follow  the  movements  of  the  operator.  J.  R. 
Gumming  suggests  the  one  shown  in  Fig.  154.  A  |-in.  air  pipe 
is  fastened  to  the  gas  torch  by  a  light  iron  clip.  The  air  pipe 
is  connected  by  a  light  hose  to  the  air  supply.  By  the  exercise 
of  a  little  ingenuity  in  making  this  attachment,  an  operator 
can  keep  his  hands  and  face  reasonably  cool  on  many  jobs  that 
would  otherwise  make  him  exceedingly  uncomfortable, 


EXAMPLES  OF  WELDING  JOBS 


203 


The  way  to  prepare  seams  in  boiler  and  tank  welds  has 
already  been  shown,  and  only  one  example  will  be  given.  Fig. 
155  shows  a  tank  which  in  use  has  to  stand  a  pressure  of  from 
200  to  300  Ib.  It  is  4  ft.  in  diameter  and  5  ft.  long.  The 
shell  is  made  of  g-in.  plate  and  the  dished  bottom  of  J-in. 
plate.  The  longitudinal  seam  is  welded,  and  the  bottom  welded 
to  the  shell  in  6  hr.,  at  less  than  the  cost  of  riveting,  and  no 
caulking  is  needed. 

There  have  been  extensive  tests  on  the  strength  of  gas-torch 


FIG.  155.— A  Welded  Tank. 


welds  on  boiler  plate  and  the  following  results  are  given  by  the 
Oxweld  Company: 


No.  of 

Area  in 

Breaking 

Stress  per 

Efficiency 

Specimen 

Dimensions 

Sq.In. 

Load 

Sq.In. 

of  Weld 

1 

1.522  x  0.393 

0.598 

25,130 

42,000 

84% 

2 

1.554X0.380 

0.592 

23,000 

42,800 

8(5.6% 

This  efficiency  is  figured. on  the  basis  of  50,000  Ib.  per  square 
inch  as  the  ultimate  tensile  strength  of  the  material,  elongation 
V16  of  an  inch  in  2  in.  as  welded,  or  about  9.3  per  cent. 

The  average  of  a  number  of  similar  tests  taken  at  random 
from  a  considerable  list  was  79  per  cent. 

A  comparison  between  the  cost  of  welding  and  riveting 
shows  that  up  to  certain  thicknesses  of  plate,  notably  f  in., 
welding  is  cheaper  per  lineal  foot  than  riveting.  On  heavier 


204 


GAS  TORCH  AND  THERMIT   WELDING 


material  than  this,  however,  the  cost  is  usually  about  the  same 
as  good  riveting  practice. 

The  speed  and  cost  per  foot  of  welding  with  an  Oxweld 
torch  for  different  thicknesses  of  plate  are: 


Thickness  of 

Lin.Ft.  per 

Cost  per 

Metal,  In. 

Hour  Welded 

Foot 

1/8 

20 

$0.04 

3/16 

15 

.06 

1/4 

10 

.09 

3/8 

6.5 

.23 

1/2 

6.0 

.27 

5/8 

4.5 

.35 

3/4 

3.0 

.60 

1 

2.0 

1.20 

This  table  is  compiled  from  results  obtained  from  actual 
shop  practice.  The  price  of  oxygen  is  figured  at  2  cents  per 
cubic  foot,  acetylene  at  1  cent  and  labor  at  30  cents  per  hour. 
Other  gas  and  labor  costs  can  readily  be  substituted  to  meet 
any  local  conditions. 

RAIL  BONDING 

Electric  rail  bonding,  such  as  shown  in  Fig.  156,  is  very 
easily  done  with  the  gas  torch.  Fig.  157  shows  a  welder  at 


FIG.  156. — Electric  Bails  and  Welded  on  Bond. 

work  on  a  job  of  this  kind.  The  apparatus  used  is  mounted 
on  a  special  truck  so  as  to  be  easily  moved  along  the  rails  from, 
one  joint  to  the  next  requiring  bonding. 


EXAMPLES  OF  WELDING   JOBS 


205 


The  filling  up  of  blowholes,  cold  shuts  and  cracks  in  castings 
of  various  kinds  is  well  known  to  most  foundry  workers,  but 
the  building  up  of  worn  or  over-machined  parts  is  not  so 
familiar  to  the  general  run  of  mechanics. 

A  good  example  of  the  reclaiming  of  an  expensive  casting 
worn  in  service  is  shown  in  Fig.  158.  This  is  the  casing  of 
a  circulating  pump.  A  strip  of  metal  about  3  in.  wide  and  J 
in.  thick  had  to  be  built  up  around  the  entire  inside  edge  of 
the  casting.  The  work  was  done  by  two  operators  working  as 


FIG.  157. — Bond  Welding  Outfit  in  Use. 

shown.  The  added  metal  was  then  ground  smooth  enough  for 
the  purpose  and  the  casing  put  back  in  service. 

Building  up  worn  pods  on  steel-mill  rolls  is  shown  in  Fig. 
159.  A  rough  brick  furnace  is  built  around  the  end  to  be 
welded  and  charcoal  used  to  heat  up  the  work  to  save  gas. 
The  welding  in  this  case  was  done  with  thermalene,  but  any 
good  gas  outfit  may  be  used  with  good  results. 

The  large  chain  belt  links,  Fig.  160,  were  cut  undersize  on 
the  corners  and  were  reclaimed  by  building  up  as  shown. 

Aluminum  automobile  transmission  or  other  castings  often 
come  through  slightly  defective.  To  recast  them  would  mean 
a  duplication  of  costs  in  cores,  molds,  handling  and  turning, 


206  GAS  TORCH  AND  THERMIT  WELDING 


FIG.  158. — Building  Up  Worn  Parts  of  Large  Pump. 


FIG.  159.— Welding  Pods  on  Steel-Mill  Rolls. 


EXAMPLES  QF  WELDING  JOBS 


207 


FIG.  160. — Building  Up  Over-Machined  Chain  Links. 


FIG.  161. — Filling  Blowholes  in  an  Aluminum  Gear  Case. 


208 


GAS  TORCH  AND  THERMIT  WELDING 


which  would  mean  a  considerable  loss.  They  are  welded — the 
holes  filled  with  similar  metal  from,  a  "filler-rod"  as  shown 
in  Fig.  161 — at  a  cost  of  but  a  few  cents  each  and  they  pass 
inspection  as  being  as  good  as  perfect  castings. 

Through  error  four  cast-brass  U-plates  for  rudder  frames, 
Fig.  162,  weighing  1000  Ib.  each,  were  made  6  in.  too  long. 

To  repour  these  plates  would  have  held  up  some  important 


FIG.  162. — Brass  Eudder  Frame  Salvaged  by  Welding. 

work  and  the  expense,  including  change  of  pattern,  would  have 
been  very  high.  The  mistake  was  quickly  and  economically 
corrected  by  cutting  6  in.  out  of  each  as  shown  by  the  illus- 
tration and  welding  the  frames  together  again. 

A  REMARKABLE  CYLINDER  WELDING  JOB 

"Writing  in  the  American  Machinist,  Jan.  8,  1920,  L.  M. 
Malcher,  superintendent  of  the  Chicago  shop  of  the  Oxweld 
Acetylene  Co.,  says:  One  of  the  5000-hp.  Allis-Chalmers  twin 
tandem  compound  reversing  steel  rolling  mill  engines  at  the 
Farrell  works  of  the  Carnegie  Steel  Co.,  Farrell,  Penn.,  that 
had  been  doing  its  full  share  in  helping  to  win  the  war 
broke  down  two  weeks  after  the  signing  of  the  armistice.  In 
the  accident,  besides  other  parts,  the  left-hand  low-pressure 


EXAMPLES   OF  WELDING   JOBS 


209 


steam  cylinder,  Fig.  163,  70  in.  inside  diameter,  was  badly 
fractured,  as  a  result  of  the  breaking  of  a  connecting-rod  at  the 
moment  of  reversal. 

It  would  have  taken  at  least  three  to  three  and  one-half 
months  to  obtain  a  new  cylinder,  in  case  the  broken  one  could 
not  be  repaired  in  a  shorter  time ;  besides  throwing  360  men  out 
of  employment.  The  broken  cylinder  was  of  such  size  and  the 
damage  done  was  of  such  character  that  a  decision  whether 


tfiG.  163. — Wrecked  Low-Pressure  Cylinder. 

The  seven  cracks  ranged  from  1  £6  §  ft.  in  length  and  2|  to  3g  in.  in  depth  and 
are  shown  V-grooved  by  chipping  preparatory  to  welding. 

the  cylinder  was  to  be  renewed  or  repaired  involved  a  risk 
on  the  part  of  the  management. 

Although  it  was  decided  that  consideration  of  expense  be- 
tween the  cost  of  purchasing  a  new  cylinder  and  the  repairing 
of  the  old  one  were  of  secondary  importance,  the  cost  of  repair- 
ing was  estimated  to  be  about  one-third  that  of  a  new  cylinder. 

Decide  to  Make  Repair. — The  officials  of  the  company  after 
having  made  a  careful  investigation  quickly  decided  in  favor 
of  oxy-acetylene  welding.  They  called  upon  the  job  welding 
shop  of  the  Oxweld  Acetylene  Co.,  Chicago,  111.,  to  meet  the 


210 


GAS  TORCH  AND  THERMIT  WELDING 


emergency.  Three  expert  welders,  accompanied  by  all  necessary 
equipment,  went  immediately  to  Farrell  and  completed  the  job 
under  the  direction  of  the  writer. 

The  fractures   of  the   cylinders   were   what   are   commonly 
known  as  "end  breaks";  that  is,  the  cracks  are  on  the  extreme 


FIG.  164. — Preheating  Crack  in  Low-Pressure  Cylinder  by  Means  of 

Charcoal  Fire. 

outside  end  of  the  casting.  As  a  rule  it  is  only  necessary  to 
preheat  the  casting  locally  (Fig.  164),  and  while  the  heat  will 
radiate  into  the  casting  to  some  extent,  the  intensity  is  not  enough 
to  harm  any  portion  by  warping  or  shrinkage.  The  total  time 
consumed  in  repairing  the  low-pressure  cylinder,  including 
chipping,  preheating  and  welding,  was  72  hours. 

While  dismantling  the  engine  a  fracture  was  discovered  in 


EXAMPLES  OF  WELDING   JOBS 


211 


the  right-hand,  42-in.  diameter,  high  pressure  cylinder.  This 
fracture  also  was  repaired  in  about  18  hours.  It  took  just 
seven  days  from  the  time  the  order  was  placed  to  complete  the 
entire  job. 


FIG.  165.— Welding  the  Low-Pressure  Cylinder. 

Asbestos  paper  was  used  to  protect  workers  and  retain  heat  from  preheating  fire. 
Note  the  extra  long  torches  and  rods  required  for  the  long  cracks. 

The  data  covering  this  work  are  given  in  detail  in  the  accom- 
panying table. 


Low-Pressure 
Steam    Cylinder 

Cylinder  bore 5  ft.  10  in. 

Stroke  4  ft.  6  in. 

Weight  of  cylinder 13  tons. 

Thickness  of  iron  casting 2f  to  3|  in. 

Total  length  of  weld 22  ft.  2  in. 

Preparing  and  preheating  casting..  27  hr. 

Welding  casting 45  hr. 

Oxygen  consumed 2850  cu.ft. 

Acetylene  consumed 2845  cu.ft. 

Cast  iron  welding  rods 390  Ib. 

Flux    25  Ib. 

Number  of  welders 3 

Period  of  welding  shifts 10  and  30  mm. 


High-Pressure 
Steam   Cylinder 

3  ft.  6  in. 

4  ft.  6  in. 

5  tons 

3£  to  6  in. 

4  ft.  6  in. 

9*  hr. 

8i  hr. 

650  cu.ft. 

650  cu.ft. 

110  Ib. 

10  Ib. 

3 

10  and  30  min. 


212 


GAS   TORCH  AND  THERMIT  WELDING 


FIG.  166. — Welding  of  Low-Pressure  Cylinder  Completed. 


FIG.   167. — Flange  Welded  on  the   5-Ton  High-Pressure  Cylinder. 
Weld  4|  ft.  long,  3|  to  6  in.  deep. 


EXAMPLES  OF  WELDING  JOBS  213 

While  welding  inside  of  the  cylinder  castings,  as  shown  in 
Fig.  165,  the  men  relieved  one  another  every  10  min.  because 
of  the  extreme  heat  deflected  back  on  them  during  the  welding 
operation.  On  the  outside  welding,  however,  the  heat  was  not 
so  intense  and  the  men  relieved  one  another  every  30  min. 

After  the  engine  cylinders  were  machined,  it  was  almost  im- 
possible to  determine  where  the  cracks  had  occurred,  as  can 
be  seen  from  Figs.  166  and  .167. 

The  total  cost  of  the  complete  repair  represented  but  a 
small  fraction  of  the  replacement  cost,  but  even  this  saving 
is  insignificant  when  compared  with  the  disorganization  which 
would  have  resulted  from  the  laying  off  of  a  large  body  of 
trained  workmen  and  with  the  enormous  loss  that  would  have 
been  entailed  in  a  stoppage  of  production. 


WELDING  HIGH  SPEED  TOOL  TIPS  TO  LOW  CARBON  SHANKS 

The  welding  of  tips  of  high  speed  steel  to  low  carbon  shanks 
is  perfectly  feasible  and  several  methods  of  performing  this  work 
are  in  successful  use.  As  a  means  of  lowering  costs  of  produc- 
tion the  process  commends  itself  to  manufacturers,  engineers 
and  plant  managers,  says  the  Welding  Engineer. 

The  principal  reasons  for  the  failures  of  the  welder  who 
attempts  this  class  of  work  is  because  of  his  ignorance  of  the 
class  of  steel  he  is  attempting  to  weld  and  because  of  a  lack  of 
practice.  Therefore,  it  is  plain  that  to  acquire  skill  in  the 
welding  of  high  speed  tips  to  low  carbon  steel  the  operator 
must  not  be  discouraged  by  a  few  failures,  but  must  master  the 
problem  by  study  and  practice. 

So  far  as  the  low  carbon  steel  used  as  shanks  is  concerned, 
this  steel  may  be  roughly  divided  into  three  general  classes: 
Cold  drawn,  open  hearth  and  Bessemer.  The  high  carbon  steels 
are  more  numerous  and  many  metals  enter  into  their  com- 
position. No  doubt  the  bulk  of  the  welder's  failures  would 
be  eliminated  if  he  had  a  perfect  understanding  of  the  varied 
and  intricate  analysis  of  many  of  the  high  carbon  steels  of  the 
day.  He  often  fails  to  appreciate  that,  controlling  a  heat  of 
6300  deg.  F.  he  plays  it  unnecessarily  long  on  a  steel  which 
melts  at  from  1800  deg.  to  2500  deg.  F.,  which  results  in  burning 
the  metal.  In  the  mills  where  such  steel  is  made,  should  a  furnace 


214  GAS  TORCH  AND  THERMIT  WELDING 

be  allowed  to  reach  such  a  temperature,  an  entire  heat  would 
be  destroyed. 

The  first  step  in  welding  high  speed  tips  to  low  carbon 
shanks  is  the  preparation  of  the  shank,  which  is  beveled  as  shown 
in  Fig.  168.  The  tip  of  high  speed  steel  is  not  to  be  beveled. 
The  shank  and  tip  should  then  be  sand  blasted,  after  which  the 
sand  dust  should  be  wiped  off  the  surfaces  to  be  welded.  It  is 
good  practice  to  preheat  both  the  shanks  and  the  tip  to  a  cherry 
red  (about  1375  deg.  F.).  Then  build  up  f  in.  of  metal  on 
the  surface  of  the  shank  that  is  to  be  welded,  and  also  on  the 
surface  of  the  tip  which  is  to  be  welded,  using  a  3/16  or  I  in. 
nickel  steel  welding  rod  and  a  flux  such  as  is  used  for  cast  iron. 


FIG.  168.— One  Method  of  Preparing  the  Shank  and  Tip. 

Then  place  the  tip  in  the  position  it  is  to  occupy  and  tack  it 
and  weld  one  side  with  a  nickel  steel  rod.  A  flux  is  not  neces- 
sary. Turn  the  tool  over  and  weld  the  other  side.  Both  sides 
should  be  welded  from  the  end,  progressing  toward  the  heavy 
portion  of  the  shank. 

The  reason  for  this  is  as  follows :  The  low  carbon  steel  shank 
will  absorb  heat  more  rapidly  than  the  tip.  As  the  flame  is 
progressing  towards  the  shank  the  tip  is  therefore  subjected 
to  as  little  heat  as  possible,  and  the  shank  will  absorb  the 
most  of  it. 

Now  set  the  tool  up  and  weld  the  sides  and  top,  where  the 
high  speed  steel  joins  the  low  carbon  shank.  In  order  to  reduce 
as  much  as  possible  the  interval  between  the  beginning  and  the 


EXAMPLES  OF  WELDING  JOBS  215 

ending  of  the  welding  operations  a  sufficiently  large  tip  should 
be  used  and  care  should  be  taken  that  the  flame  is  not  played 
on  one  spot  too  long,  or  the  metal  will  be  burned. 

It  will  be  noted  that  a  nickel  steel  welding  rod  is  recom- 
mended, although  in  justice  to  some  very  capable  welders  it 
may  be  said  that  in  certain  shops  both  Norway  or  Swedish  iron 
rods  and  Vanadium  steel  is  being  used.  The  author  believes, 
however,  that  the  results  attained  justify  the  statement  that 
nickel  steel  rods  are  preferable. 

Many  welders  overlook  the  fact^that  the  physical  properties 
of  high  speed  steel  and  ordinary  tool  steel  are  so  different  that 
strains  are  set  up  by  welding.  Therefore  it  is  essential  that  the 
welded  tools  be  heat  treated  before  cooling  from  a  welding 
operation.  When  possible  a  furnace  should  be  used  for  this 
purpose.  If  the  life  of  the  tool  is  of  but  short  duration,  it  is 
sufficient  to  bury  it  in  lime  or  asbestos  as  soon  as  the  welding 
operation  is  completed.  Another  good  method  is  to  place  the 
tool  on  end  and  in  a  tank  which  contains  any  good  mineral  oil. 
This  tempering  or  hardening  process  should  take  place  directly 
after  the  welding  operation  and  before  the  tool  cools. 

As  was  pointed  out  at  the  beginning  of  this  article,  in  the 
welding  of  high  speed  tips  to  low  carbon  shanks,  much  depends 
on  the  operator.  In  ordinary  tool-room  work  when  a  difficult 
or  intricate  tool  or  jig  has  to  be  made,  the  foreman  selects  one 
of  his  best  men  to  do  the  work.  In  the  case  of  failure,  the 
human  element  is  blamed.  "With  the  oxy-acetylene  process,  how- 
ever, the  blame  is  too  frequently  placed  on  the  process  or  the 
apparatus.  Too  often  the  verdict  is,  "No  good  for  that  kind 
of  work."  This  snap  judgment  is  usually  due  to  a  lack  of 
knowledge  on  the  part  of  both  the  welders  and  their  foremen. 
In  handling  work  of  such  a  special  character  as  welding  tools 
it  should  be  understood  that  the  welder  should,  if  he  is  not 
already  experienced  in  that  work,  be  given  an  opportunity  to 
study  and  practice  and  his  first  failures  should  neither  condemn 
him  or  the  process.  The  results  to  be  derived  from  patience 
will  justify  the  expense  of  the  welder's  training. 

G.  A.  Hastings,  in  the  American  Machinist,  says:  "Our 
high-speed  steel  scraps  consisted  of  all  sorts  of  short  ends. 
Owing  to  the  high  price  of  steel  we  decided  to  try  oxy-acetylene 
welding  to  utilize  the  ends  on  a  mild-steel  shank.  We  pre- 


216  GAS  TORCH  AND  THERMIT  WELDING 

pared  for  the  weld,  as  shown  in  Fig.  169,  and  have  turned 
out  lathe,  shaper  and  planer  tools  that  give  entire  satisfaction. 
The  high-speed  points  were  cut  with  a  hot  set  and  ground 
to  the  proper  shape,  the  welding  edges  being  beveled  toward 
the  center  at  about  45  deg.  The  shank  was  made  in  the  same 
way  and  the  weld  made  with  an  ordinary  steel-welding  rod. 
We  figured  that  making  the  weld  at  an  angle  of  45  deg.  from 


FIG  169  — Another  Method  of  Preparing  the  Shank  and  Tip. 

the  base  would  give  the  welded  point  a  better  support  from  the 
end  of  the  shank  and  reduce  the  stresses  at  the  weld. 

The  first  tool  made  cost  about.  35c.  excluding  the  somewhat 
doubtful  value  of  the  high-speed  scrap  used  for  the  point. 
Later  tools,  of  course,  cost  less. 

Regarding  Presto-0-Lite  Co.  practice,  A.  F.  Brennan  says: 
* '  The  weld  is  made  in  the  following  manner :  Both  the  machine 

.bevel  from  both  Sides 
for  Yielding 


••-High-Speed  Steel 
FIG.  170. — Prest-O-Lite  Tool  Welding  Practice. 

steel  and  the  high-speed  steel  are  beveled  from  two  sides  by 
grinding,  as  shown  in  Fig.  170.  It  is  important  that  this 
bevel  extend  clear  to  the  center  of  the  piece  and  that  the 
angle  be  a  generous  one — at  least  90  deg.  It  has  been  found 
that  a  nickel-steel  welding  rod  made  of  a  low-carbon  steel 
containing  about  3  per  cent  nickel  gives  the  best  ,results,  and 
no  flux  is  used. 

1  'The  weld  should  be  executed  just  as  though  both  pieces  were 
of  machine  steel,  except  that  greater  care  should  be  taken  to 


EXAMPLES  OF  WELDING  JOBS 


217 


insure  the  penetration  clear  to  the  center  of  the  parts  being 
welded;  and  it  will  probably  be  found  necessary  to  "puddle" 
or  "work"  the  molten  metal  with  the  filling  rod,  as  some 
grades  of  high-speed  steel  do  not  flow  readily  under  the  torch. 
Wherever  possible,  the  weld  should  be  built  up  or  reinforced, 
although  in  some  cases  this  is  impossible,  as  when  the  welded 
portion  is  to  be  used  inside  the  tool  holder.  In  such  cases  the 


Right-hand  Roughing  K-  .......  2  ......  -x 

Too!  Prepared         \(Hgh-speed  Steel) 
V"       ^ 


"*! 


for  Welding 


Offset  on  of  her 

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Weld 

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-1      Roughing  To 

FIG.  171. — Details  of  Tools  with  Oxy-acetylene-welded  Points. 

weld  has  to  be  ground  off  level.  After  the  weld  is  completed, 
the  tool  can  be  ground  and  tempered  in  the  usual  manner. 

"A  tool  1  X  1  in.  can  be  welded,  if  properly  beveled,  in  about 
10  min.  with  a  No.  6  tip.  The  oxygen  consumption  for  this 
operation  is  about  5  cu.ft,  and  the  acetylene  consumption  is 
approximately  the  same.  On  this  basis  the  labor  costs  are  5c., 
acetylene  and  oxygen  lOc.  each,  and  filling  material  5c. 

"I  have  never  welded  on  any  points  of  high-speed  steel  less 


218  GAS  TORCH  AND  THERMIT  WELDING 

than  about  an  inch  and  a  half  long;  but  if  the  material  is 
properly  handled,  I  believe  that  this  length  could  be  reduced. 

"When  it  is  remembered  that  the  price  of  high-speed  steel 
has  risen  greatly,  the  practice  is  worth  considering. 

"Further,  there  are  oftentimes  short  ends  of  high-speed  steel 
that  are  not  long  enough  for  use.  They  are  usually  sold  for 
scrap,  but  may  be  used  to  advantage  by  this  method." 

The  practice  of  the  lloot  &  Vandervoort  Engineering  Co., 
East  Moline,  111.,  is  as  follows:  The  mild-steel  shank  and  high- 
speed steel 'point  or  bit  are  shaped  as  shown  at  A  and  B,  Fig. 
171.  The  details  give  the  proportions  of  one  kind  of  round- 
nose  turning  tool  for  roughing  cuts,  and  for  both  right-hand 
and  left-hand  setting.  The  shanks  and  points  may  be  forged 
or  machined  to  the  shapes  given,  but  in  the  case  of  forgings 
the  angular  surfaces  must  be  ground  to  free  them  from  scale. 

When  welding,  the  tool  is  laid  on  its  side  and  the  parts 
blocked  up  so  that  they  are  in  proper  relation  to  each  other. 
They  are  then  welded,  using  an  oxy-acetylene  welding  outfit,  with 
a  torch  having  a  tip,  giving  a  flame  about  f  in.  long.  Round 
Norway  iron  8/16  in.  in  diameter  is  used  for  filling,  and  care 
is  taken  to  prevent  the  flame  from  directly  touching  the  high- 
speed steel  point.  The  operator  keeps  the  welding  rod  between 
the  flame  and  the  piece  of  high-speed  steel.  The  angular  grooves 
on  the  sides  of  the  tool,  as  shown  at  J5,  are  filled  up  a  little 
more  than  flush  and  most  careful  attention  is  given  to  see  that 
a  first-class  weld  is  made. 

After  the  tool  is  welded,  no  hammering  of  any  kind  is  done 
on  it,  and  all  shaping  is  done  by  grinding.  After  rough  grind- 
ing, the  tool  is  hardened  in  the  usual  manner,  and  then  after 
finish  grinding,  it  is  ready  for  use. 

The  finished  shape  and  dimensions  of  a  right-hand  roughing 
tool  made  by  this  method  are  shown  at  (7,  and  a  similar  left- 
hand  tool  at  D. 

In  another  article,  Herbert  V.  Ludwick  writes:  Owing  to 
the  high  cost  of  high-speed  steel,  the  practice  of  welding  high- 
speed tips  to  machine-steel  shanks  is  of  interest  to  manufacturers. 
Welding  a  high-speed  steel  tip  to  a  machine-steel  body  for 
cutting  off  tools  for  automatic'  machinery  has  been  more  or  less 
a  difficult  problem,  owing  to  the  shock  the  weld  has  to  stand 
from  the  constant  chatter  of  the  stock  against  the  tool. 


EXAMPLES  OF  WELDING  JOBS 


219 


Take  two  pieces  of  high-speed  steel  A,  Fig.  172,  f  in.  square 
by  2  in.  long,  and  grind  a  i-in.  radius  on  the  end  of  each.  A 
rough  machine-steel  body  is  milled  at  both  ends  as  illustrated 
at  B.  The  parts  are  assembled  and  put  in  the  jig  C,  which  is 


showing    Block 
clomped  in  Jig  C 


Contour  of  Blade  after  Welding 


16  Threads  per 
lnch.U-S.Std 
Right  Hand 

,  !    .  h 


Contour  of  finished  Blcwle 


FIG.  172.— Jig  for  Welding  High-speed  Steel  Tip  to  Machine-steel  Body. 

made  from  two  pieces  of  J  X  J-in.  machine  steel  D  and  £. 
They  are  fastened  with  two  clamps  F,  made  of  flat  steel  held 
by  \-  or  f-in.  U-bolts  G.  Wing  nuts  should  be  used  if  at  all 
possible,  as  they  are  easily  and  quickly  adjusted. 


220     .  GAS  TORCH  AND  THERMIT  WELDING 

The  reason  for  using  the  jig  is  that  when  the  flame  of  the 
torch  is  directed  on  the  places  to  be  welded  it  heats  the  tips 
and  the  body  of  the  blade  very  quickly  and  causes  the  steel  in 
the  blade  to  expand  before  the  jig  has  time  to  get  very  hot. 
These  two  bodies,  when  heated  until  they  run  at  the  weld,  are 
forced  together  by  their  expansion,  resulting  in  a  better  weld. 

The  work  should  be  removed  from  the  jig  quickly  and  placed 
in  powdered  lime  or  bar  sand,  to  prevent  chilling  and  the 
formation  of  hard  brittle  spots  in  the  weld,  which  are  difficult 
to  machine  even  after  the  regular  annealing  process. 


CHAPTER  XIII 
WELDING  JIGS  AND  FIXTURES 

Where  a  welding  shop  does  a  general  line  oi*  work  which 
includes  everything  that  comes,  there  should  be  an  ample  assort- 
ment of  drilled  straps,  angle  irons,  bolts,  V-blocks,  clamps, 


FIG.    173. — Table   for  Holding  Welding   Work. 

plates  and  the  like.  Good  supplies  of  fireclay  and  plaster  of 
paris  are  also  very  desirable  for  supporting  or  holding  irregular 
work  that  is  apt  to  collapse  or  get  out  of  line.  Many  times, 
a  table  such  as  shown  in  Fig.  173  will  answer  for  certain  jobs. 

221 


222  GAS  TORCH  AND  THERMIT  WELDING 


FIG.  174. — Holding  Pipe  for  Welding. 


FIG.  175.— V-Blocks  for  Holding  Shafts. 


WELDING  JIGS  AND  FIXTURES  223 

The  top  of  this  table  is  made  of  a  "grated"  slab  of  cast  iron 
supported  on  a  welded  angle-  and  strap-iron  frame.  The  slots 
provide  means  for  the  insertion  of  clamping  bolts.  A  table 
similar  to  this  can  easily  be  made  in  any  welding  shop. 

Pipe  welding  is  a  very  common  and  re-occurring  job  in  most 
shops.  Some  rig  up  V-blocks,  rollers  or  other  devices,  but  the 
method  shown  in  Fig.  174  is  very  good.  It  is  simply  a  piece 
of  angle  iron  placed  on  iron  horses  as  illustrated.  The  ends 
of  the  pipe  to  be  welded  are  cut  square  and  the  outside  ground 
back  for  about  two  or  three  inches  to  remove  rusty  scale  and 
dirt.  On  long  pieces  of  pipe  the  grinding  may  be  done  with  a 
portable  electric  grinding  machine  while  the  end  of  the  pipe 
sticks  out  a  foot  or  so  from  the  end  of  the  channel  iron.  The 
pipe  in  this  case  remains  still  and  the  grinding  machine  is 
moved  around  it  as  the  operator  stands  in  front  of  the  pipe  end. 


FIG.  176. — Jig  for  Holding  Crankshafts. 

The  short  or  easily  handled  pieces  of  pipe  may  be  ground  on 
a  stationary  grinding  machine. 

The  best  part  about  using  an  angle  iron  is  that  the  pieces 
of  pipe  to  be  welded  are  held  in  line  while  being  tacked  together. 
On  ordinary  sizes  the  welder  will  have  no  difficulty  in  turning 
the  pipe  as  he  welds.  On  heavy  pipe  some  form  of  rollers  will 
be  found  very  convenient. 

A  very  simple  way  to  weld  straight  shafts  is  shown  in  Fig. 
175.  Here  the 'shaft  simply  rests  on  high  V-blocks  which  keep 
it  in  line  but  do  not  interfere  with  expansion  or  contraction. 

A  jig  for  holding  a  motor  crankshaft  broken  in  the  shaft 
is  shown  in  Fig.  176.  The  main  part  of  the  crankshaft  is 
clamped  to  three  V-blocks.  The  bases  of  these  V-blocks  are 
grooved  to  fit  over  a  tongue  in  the  baseplate,  so  that  they  may 
be  slid  along  in  order  to  adjust  them  to  various  sizes  of  crank- 
shafts, and  yet  keep  them  in  line.  The  V-block  holding  the 


224  GAS   TORCH  AND  THERMIT   WELDING 


FIG.  177. — An  Adjustable  Crankshaft  Jig. 


PIG.  178. — Welding  a  Broken  Web  in  the  Jig. 


WELDING  JIGS  AND  FIXTURES 


225 


short  piece  to  be  welded  on  is  made  in  the  same  way,  but  the 
piece  should  not  be  clamped  in  solidly  but  should  be  so  held 
that  it  can  move  lengthwise.  This  may  be  done  by  clamping 
loosely  or  else  having  the  V-block  free  to  move  along  the  tongue 
The  rigid  clamping  of  all  parts  would  cause  distortion  and 
springing  of  the  crankshaft. 

The  device  shown  in  Fig.  177  is  in  use  in  the  Oxweld  shop. 


FiG.  179. — Aluminum  Crankcase  Stiffened  by  Angle  Iron. 


FIG.  180. — Angle  Iron  Applied  to  Another  Job. 


Four  V-blocks  are  made  to  slide  on  bars,  as  illustrated,  and 
may  be  clamped  wherever  desired.  Each  V-block  carries  its 
own  clamping  screw  for  holding  the  work.  For  ordinary  shaft 
welding  the  table  may  be  used  in  a  horizontal  position,  as 
shown,  but  for  welding  breaks  in  webs  the  table  may  be  tilted 
as  shown  in  Fig.  178.  This  illustration  also  shows  the  use  of 
a  coal-gas  and  air  torch  to  heat  the  work  while  the  welder  is 
using  the  welding  torch. 


226  GAS  TORCH  AND  THERMIT  WELDING 


FIG.  181. — Crankcase  with  Angle  Iron  and  Bearing  Mandrels  in  Place. 


FlG.  182. — Motorcycle  Manifold  Welding  Jig. 


WELDING  JIGS  AND   FIXTURES 


227 


Crank  cases  or  other  automobile  parts  may  be  held  in  order 
to  prevent  distortion  as  much  as  possible,  as  shown  in  Fig.  179. 
In  this  case  angle  irons  and  short  bolts  with  wingnuts  are  all 
that  are  needed.  The  patch  to  be  welded  in  is  shown  tacked 
in  place  at  A.  Another  application  is  shown  in  Fig.  180.  The 
patch  B  has  been  tacked  in  two  places  ready  for  w.elding. 


FIG.  183.— A  Welded  Motorcycle  Manifold. 


FIG.  184.— A  Sheet-Metal  Roller  Welding  Jig. 

In  Fig.  181  both  angle  irons  and  mandrels  are  used  in  the 
bearings.  These  mandrels  may  be  solid  or  of  pipe  to  fit  the 
bearings.  Sometimes,  wrhere  it  is  necessary  to  keep  the  bearings 
cool,  a  pipe  with  elbows  screwed  on  each  end  may  be  clamped 
in.  With  the  ends  of  the  elbows  up,  the  pipe  may  be  filled  with 
water. 

The  Henderson  Motorcycle  Co.  uses  the  jig  shown  in  Fig. 


228  GAS   TORCH  AND   THERMIT  WELDING 


FIG.  185. — A  Welded  Conveyor  Roller. 


FIG.    186. — Large  Sheet-Metal   Cylinder   Welding  Jig. 


WELDING   JIGS   AND   FIXTURES 


229 


182  to  hold  the  parts  of  their  exhaust  manifolds  while  welding. 
The  construction  and  operations  are  obvious.  A  welded  mani- 
fold is  shown  in  Fig.  183. 

Holding   Sheet-Metal   Cylinders. — A   very   simple   welding 
jig  is  shown  in  Fig.  184.     This  consists  of  four  castings:  the 


FlG.  187. — Apparatus  for  Welding  Ends  in  Cylinder  or  Tanks. 

base,  two  side  pieces  and  the  hollow  mandrel.  The  cylinders 
welded  are  6  in.  in  diameter  and  8£  in.  long,  made  of  |-in. 
plate.  They  are  used  to  make  the  conveyor  roller  shown  in 
Fig.  185.  The  seam  is  welded  in  three  minutes. 

Another  cylinder  welding  jig  is  shown  in  Fig.  186.     This 
is  in  use  in  the  Thermalene  shop.     The  edges  of  the  cylinder 


230 


GAS  TORCH  AND  THERMIT  WELDING 


o 
PH 
be 


WELDING  JIGS  AND   FIXTURES  231 

to  be  welded  are  held  up  to  the  V-channel  from  underneath  by 
a  bar  locked  in  place  by  bolts  and  large  wingmits. 

The  speed  for  welding  sheet  metal  will  of  course  vary  widely, 
but  the  following  approximate  results  on  sheet  iron  and  steel 
are  a  fair  average : 

Thickness  of  Feet  per 

metal  hour 

20  gage  40 

18      "  35 

16      "  30 

14      "  24 

12      "  22 

10      "  20 

8      "  IS 

The  welding  of  steel  barrels  of  about  30  to  35  gal.  capacity, 
used  for  oil  or  gasoline,  can  be  done  by  an  operator  of  average 
skill  at  the  rate  of  16  to  18  per  day.  These  barrels  are  made 
of  12-,  14-,  or  18-gage  sheet  steel,  and  require  one  seam  weld, 
two  complete  end  welds,  two  bungs  welded  in  and  a  reinforcing 
ring  welded  on  each  end. 

In  welding  the  ends  on  cylinders  or  drums,  the  device  shown 
in  Fig.  187  is  sometimes  used.  The  work  rests  on  a  turn  table 
which  is  rotated  by  the  welder's  foot.  A  supporting  arm  and 
a  suspension  spring  assist  the  welder  in  holding  the  gas  torch. 

The  method  of  welding  gas  containers  for  war  use  with 
Oxweld  apparatus  is  shown  in  Fig:  188.  As  shown  at  the  right, 
the  container  bottoms  are  welded  in  while  resting  on  rollers 
set  on  an  inclined  base  in  such  a  way  as  to  present  the  work 
at  the  right  angle. 

Fig.  189  gives  a  better  view  of  the  bung  welding  apparatus, 
and  also  shows  the  excellent  method  of  suspending  the  torches 
when  not  in  use. 

LIBERTY  MOTOR  WORK 

In  describing  work  on  the  Liberty  Motor  in  the  American 
Machinist,  May  29,  1919,  H.  A.  Carhart,  mechanical  engineer 
of  the  Lincoln  Motor  Co.,  Detroit,  first  outlines  some  of  the 
electrical  welding  and  then  says:  "The  water  jacket  is  fitted 
to  the  cylinder,  and  the  latter  when  assembled,  is  placed  in  a 
clamping  fixture,  Fig.  190.  This  fixture  consists  of  a  frame 


232 


GAS  TORCH  AND   THERMIT  WELDING 


& 


WELDING  JIGS  AND   FIXTURES 


233 


with  two  jaws  which  are  placed  around  the  jacket  for  holding 
while  being  tacked.  The  equipment  used  in  this  operation  is  a 
miniature-style  Torchweld  torch,  equipped  with  a  No.  3  tip 
and  using  VS2-in.  Norway  welding  wire. 

"After  being  tacked,  the  cylinder  is  placed  in  another  fixture, 
and  the  bottom  of  the  jackets  are  welded  to  the  jacket  flange 
on  the  cylinder.  The  fixture  employed  in  this  operation  is  a 
fork  made  of  steel  1J  in.  wide,  so  shaped  as  to  fit  the  top  of 
the  cylinder  and  thus  keeping  it  in  an  inverted  position.  Weld- 
ing the  bottom  first  was  considered  to  be  an  advantage  as  the 


FIG.  190. — Tacking  Jacket  for  Liberty  Cylinder. 

heat  applied  at  that  point  had  a  tendency  to  draw  the  jackets 
closer  together.  It  was  also  considered  advisable  to  leave  an 
opening  between  the  jacket  halves  about  V16  in.  to  V32  in.  to 
take  care  of  the  contraction  which  the  different  jacket-welding 
operations  tended  to  produce. 

"The  cylinder  was  next  placed  in  a  horizontal  position  on  a 
cast-iron  table,  and  the  jacket-side  seams  were  welded.  The  welds 
were  started  from  the  bottom  proceeding  upward  to  the  port- 
holes. The  cylinder  was  then  placed  in  an  upright  position 
and  the  top  seam  completed.  The  equipment  used  in  this 


234 


GAS  TORCH  AND   THERMIT   WELDING 


operation  was  a  miniature  Torchweld  torch  equipped  with  a  No.  2 
tip  and  V16-in.  Norway  welding  wire. 

"The  next  operation  was  to  weld  the  jacket  around  the  two 
spark  plugs,  valve  guide  and  camshaft  housing  bosses.  The 
fixture  employed  in  this  operation  carries  a  pilot  upon  which  the 
cylinder  can  be  turned  circularly.  The  equipment  used  is  the 
same  as  before  except  that  a  No.  3  tip  was  found  best. 


FIG.  191.— Welding  the  Inlet  Pipe. 

"Next  came  the  welding  of  the  jacket  around  the  porthole 
flange.  The  fixture  used  in  this  operation  consists  of  a  standard 
with  a  revolving  cradle  to  lay  the  cylinder  in.  The  revolving 
motion  of  the  cradle,  together  with  the  varying  height  of  the 
standards,  gives  the  operator  easy  access  to  weld.  The  equip- 
ment used  is  a  No.  1  Torchweld  torch  equipped  with  a  No.  3 
tip  and  V16-in.  Norway  welding  wire. 


WELDING  JIGS  AND   FIXTURES  235 

"The  next  operation  consists  of  welding  both  water  pipes 
to  the  jacket  and  the  jacket  seams  between  the  valve  guide  and 
porthole  flange.  This  is  shown  in  Figs.  191  and  192,  both 
inlet  and  outlet  being  handled  in  the  same  fixture.  This  fixture 
is  equipped  with  two  devices  for  holding  the  water  pipes  in 
their  proper  position  while  being  welded  and  is  so  arranged 
that  it  can  be  oscillated  to  suit  the  position  in  which  the  operator 


FIG.  192.— Welding  the  Outlet  Pipe. 

is  welding.  The  cylinder  is  located  by  a  flat  clamp  which 
locates  the  flat  on  the  cylinder  bolt  flange  in  proper  relation 
to  the  pipe-holding  devices. 

"The  jacket  seams  are  welded  first,  followed  by  the  water 
outlet  pipe.  In  these  two  cases,  the  cylinder  is  welded  in  an 
upright  position.  The  locating  clamp  on  the  bolt  flange  flat 
is  then  released  and  the  cylinder  given  a  half-turn  to  the  op- 


236 


GAS  TORCH  AND  .THERMIT  WELDING 


posite  flat.  The  inlet  pipe  is  then  placed  in  its  holding  device 
and  welded  with  the  fixture  in  a  semi-horizontal  position  to 
suit  the  welder. 

1 '  The  cylinder  is  then  removed  and  the  water  pipes  inspected 
for  proper  location.  If  it  is  passed,  the  cylinder  is  hammered 
with  a  rawhide  hammer  to  remove  scale  and  loosen  any  poor 
weld,  after  which  it  is  tested  for  leaks.  If  leaks  are  found,  they 
are  repaired  by  expert  welders  and  returned  for  re-inspection." 

WELDING  FIXTURES  FOR  MAKING  MANIFOLDS 

Writing  in  the  American  Machinist  for  Ma~rch  25,  1920,  C.  C. 
Phelps  says:  "Several  ingenious  fixtures  are  employed  lu  great 


FIG.  193. — Fixtures  Used  in  Welding  Liberty  Motor  Manifolda. 

advantage  in  manufacturing  manifolds  for  the  Liberty  engines 
by  means  of  the  oxy-acetylene  process  at  the  plant  of  the  Ireland 
&  Matthews  '  Manufacturing  Co.,  Detroit,  Mich.  The  fixtures 
were  designed  in  accordance  with  plans  furnished  by  the  en- 
gineering department  of  the  Oxweld  Acetylene  Co.,  Newark, 
N.  J. 

"In  assembling  the  manifold  parts  in  the  fixture,  Fig.  193,  the 
five  branch  inlets  are  first  mounted  on  their  respective  pivots  A 
in  the  bed  of  the  fixture;  the  trunk  of  the  manifold  is  then 


WELDING  JIGS  AND  FIXTURES 


237 


placed  above  and  in  contact  with  the  branch  lines,  so  that 
the  openings  in  the  trunk  coincide  with  the  ends  of  the  branches, 
and,  finally,  the  five  hinged  clips  B  are  swung  into  position  and 
clamped  down  on  the  assembled  manifold  by  means  of  the  hand 
clamps.  The  end  of  the  trunk  is  bent  to  serve  as  one  of  the 
inlets  and  this  end  in  turn  is  inserted  over  the  end  pivots.  The 
fixture  shown  in  Fig.  194  serves  to  hold  the  assembled  parts  in 
perfect  alignment. 

"The  fixture  proper  is  suspended  at  the  ends  to  permit  com- 


FIG.   194. — Details  of  Fixture  Proper.     Assembled  Manifold  Indicated  by 

Dotted  Lines. 


FIG.  195. — Details  of   Swing  Support   for   Manifold   Welding  Fixture. 

plete  freedom  of  rotation,  and  the  points  of  suspension  are  so 
-located  that  the  device  will  be  in  balance  when  containing  the 
tubing.  The  support  for  the  fixture,  Fig.  195  is  mounted  on 
a  pedestal  in  such  manner  as  to  allow  rotation  in  a  horizontal 
plane.  Thus  the  operator  is  enabled  to  shift  the  work  so  that 
the  torch  flame  can  be  applied  in  the  most  advantageous  manner 
at  all  times.  Fig.  196  shows  the  complete  manifold. 

"During  the  war  this  company  manufactured  various  kinds 
of  tubes   and   manifolds   for  Liberty   and   Le   Rhone   engines, 


;  •-     ' 
-  -.  - 


CHAPTER  XIV 
WELDING    MACHINES 

Gas-torch  welding  machines  with  automatic  feed  are  used 
for  a  large  variety  of  work,  although  straight-seam  welding  is 
the  more  common.  In  this  latter  class  of  work  are  included 
sheet-metal-cylinder  side-seam  welding  and  pipe  or  tube  welding. 

A  welding  machine,  known  as  the  Duograph,  is  shown  in 
Fig.  197.  This  machine  was  made  by  the  Davis-Bournonville 
Co.  and  was  especially  designed  for  welding  the  seams  of  steel 
drums  or  containers,  insuring  a  mechanical  weld  uniform  in 
appearance  and  efficiency.  It  comprises  a  turret-top  holding 
device  with  water-cooled  arms  and  clamps  for  holding  the  steel 
drums  in  position,  permitting  the  work  being  placed  in  position 
for  welding  on  one  set  of  arms  while  the  work  on  the  opposite 
set  of  arms  is  being  welded.  The  turret  top  is  then  swung  half 
around,  the  welded  work  removed  and  another  job  set  up. 

The  gas-torch  carriage  is  moved  forward  at  a  fixed  speed 
by  power,  belt  driven,  and  is  reversed  by  means  of  a  hand- 
wheel  when  the  weld  is  finished.  Various  speeds  for  different 
thicknesses  of  metal  are  obtained  by  the  use  of  cone  pulleys. 
The  carriage  is  fitted  with  two  torches — one  above,  the  other 
below — as  shown  in  Fig.  198,  for  welding  both  sides  of  the  seam 
simultaneously.  For  very  light  welding,  one  torch  only  is  re- 
quired. Water-cooled  welding  torches  are  used.  The  No.  1 
machine  will  weld  a  36-in.  seam,  and  will  take  containers  from 
12-in.  to  36-in.  in  diameter.  The  No.  2  machine  welds  a  54-in. 
seam.  An  average  speed  of  welding  of  18-in.  per  minute  is 
obtained  on  16-gage  sheets. 

Fig.  199  is  a  close-up  of  a  man  putting  a  sheet-metal  drum 
into  position  on  one  of  the  turret  arms.  Fig.  200  shows  the 
drum  clamped  down  and  swung  into  place  ready  to  be  welded. 
This  illustration  gives  a  good  idea  of  the  operating  mechanism. 

239 


240 


GAS   TORCH  AND  THERMIT  WELDING 


t 


WELDING   MACHINES 


241 


FIG.  198. — Torch  Arrangement  on  the  Duograph. 


FiQ.  199. — Putting  a  Drum  Onto  a  Turret  Arm. 


242  GAS  TORCH  AND  THERMIT  WELDING 


FIG.  200. — Drum  in  Position  Ready  for  Welding. 


FIG.  201. — The  Finished  Seam  Weld. 


WELDING   MACHINES 


243 


Fig.  201  shows  the  seam  weld  completed  and  ready  to  be 
removed. 

A  much  simpler  machine  is  shown  in  Fig.  202.  The  opera- 
tion of  the  feeding  mechanism  is  obvious. 

A  smaller,  though  very  similar  machine,  is  shown  in  Fig. 


FIG.  202.— Heavy  Drum  Welding  Machine. 


FIG.  203. — Light  Seam  Welding  Machine. 

203.    While  the  work  shown  in  position  is  cone  shaped,  cylinders 
may  be  held  as  well. 

The  machine  shown  in  Fig.  204  is  for  welding  bottoms  onto 
tea  kettles,  cans,  drums  or  other  circular  work.  The  machine 
is  so  made  as  to  allow  for  a  considerable  range  of  adjustment 
for  different  sizes  of  work. 


244 


GAS   TORCH  AND   THERMIT  WELDING 


The  last  three  machines  mentioned  were  designed  by  Linus 
Wolf,  of  the  Thermalene  Co.,  Chicago  Heights,  111. 

A  machine  developed  at  the  plant  of  the  Edison  Storage 
Battery  Co.,  Orange,  N.  J.,  for  welding  bottoms  in  storage- 
battery  cases,  is  shown  in  Fig.  205.  This  machine  was  first  de- 
scribed in  the  American  Machinist,  Aug.  10,  1911.  The  bottom 


FIG.  204. — Machine  for  Welding  Circular  Seams. 

to  be  welded  in  is  made  of  sheet  steel  with  upturned  edges.  A 
four-part  expanding  form  is  placed  within  the  edges  of  the 
bottom  and  locked  by  turning  down  the  screw  shown  in  the 
center  of  the  case.  With  the  bottom  and  expanding  form  in 
place  as  shown,  the  case  is  "  shrunk "  to  it  and  sized  by  turning 
the  eccentric  lever  A.  The  gas  torch  B,  which  is  hinged  at  0, 
is  then  swung  down  into  welding  position  and  so  set  as  to 
throw  the  flame  correctly  onto  the  upturned  edges  of  the  bottom 


WELDING  MACHINES 


245 


and  the  case.    The  motor  is  then  started  and  the  feed  thrown 
in  by  means  of  lever  Z>. 

This  lever  operates  a  clutch  on  a  shaft  carrying  a  pinion 
meshing  with  the  oblong  gear  on  the  bottom  of  the  frame  which 


FIG.  205. — Machine  for  Welding  Oblong  Seams. 

supports  the  case.  This  moves  the  frame  and  the  seam  to  be 
welded  along  under  the  welding  flame.  When  a  corner  is 
reached  the  trip  E  throws  the  lever  F  and  slips  the  clutch  G 
into  contact  with  the  upper  teeth,  increasing  the  speed  of  the  driv- 


246 


GAS   TORCH  AND   THERMIT  WELDING 


ing  pinion  so  that  the  seam  being  welded  moves  at  the  same  speed 
under  the  flame  while  turning  the  corner  as  while  being  driven 
along  the  straight  seam.  As  soon  as  the  corner  has  been  turned 
the  lever  F  is  forced  down  by  another  trip  and  the  sun-and- 
planet  gearing  /  again  comes  into  play,  giving  a  slower  move- 
ment as  the  straight  part  of  the  seam  is  fed  under  the  flame. 


FIG.  206. — Single-Torch  Tube  Welding  Machine. 

For -bringing  the  mechanism  back  to  the  starting  point,   the 
handle  J  is  used. 

A  single- jet  tube  welding  machine  made  by  the  Thermalene 
Co.,  is  shown  in  Fig.  206.  Views  of  a  double  torch  machine 
made  by  the  same  concern,  are  shown  in  Figs.  207  and  208. 
In  a  general  way,  these  are  typical  of  all  machines  designed  to 
butt-weld  formed  tubes. 


WELDING  MACHINES 


247 


TUBE  WELDING  BY  THE  OXY-ACETYLENE  PROCESS 

Writing  in  the  American  Machinist,  Nov.  13,  1919,  F.  M. 
Smith,  Chief  Engineer  of  the  Oxweld  Acetylene  Co.,  Newark, 
N.  J.,  says:  "Tubing,  considered  merely  as  a  structural  shape, 


FIG.  207. — Duplex  Tube  Welding  Machine. 

has  the  greatest  strength  in  compression  and  bending  to  be  ob- 
tained from  any  shape  of  equal  cross-sectional  area.  Likewise, 
it  is  one  of  the  most  convenient  shapes  known.  •  In  large  work 
this  fact  has  been  applied  for  years  in  the  use  of  round  cast- 
iron  columns  and  standard  commercial  wrought-iron  pipe  of  vari- 
ous weights,  but  until  the  advent  of  welded  tubing  nothing  but 


248 


GAS  TORCH  AND   THERMIT  WELDING 


drawn  seamless  tubing  was  available  for  weights  lighter  than 
pipe  and  its  price  has  been  prohibitive  for  ordinary  purposes. 
"When  the  oxy-acetylene  welding  process  offered  a  means  of 
producing  the  substitute  for  drawn  seamless  tubing  in  the  form 
of  welded  tubing  of  thin  gage,  numerous  manufacturers  were 
so  well  impressed  with  the  possibilities  of  this  line  of  work 


ff 


FIG.  208. — Another  View   of   Duplex  Machine. 

that  they  went  into  it  on  a  large  scale.  As  a  result,  the 
product  of  the  oxy-acetylene  tube-welding  process  is  of  such 
excellent  quality  and  is  produced  so  much  cheaper  than  drawn 
seamless  tubing  that  it  is  rapidly  superseding  the  latter  form 
of  tubing  for  very  many  purposes. 

"Tubes  welded  by  the  oxy-acetylene  process  are  almost  in- 


WELDING  MACHINES  249 

variably  butt-welded;  that  is,  'in  the  tubes  as  formed  up,  the 
square  edges  lie  butt  to  butt.  The  heat  is  applied  to  the  seam 
only  and  must  be  of  an  intensity  to  raise  the  edges  immediately 
under  the  flame  to  the  fusing  point.  The  edges  are  then  pressed 
together  while  in  a  molten  condition  and  flow  into  each  other, 
forming  a  true  and  homogeneous  weld.  The  weld  may  be  upset, 
or  reinforced,  if  so  desired,  to  a  greater  thickness  than  the 
original  tubing  wall  by  compression  of  the  seam  at  the  point 
of  weld. 

"As  the  uses  of  tubing  are  principally  structural,  the  material 
from  which  it  is  made  is  usually  low-carbon  steel,  although  this 
is  not  used  as  universally  as  might  be  expected  because  old 
high-carbon  rails  make  an  excellent  and  comparatively  cheap 
raw  material  for  the  manufacture  of  tubing  by  the  hot  formed 
process,  where  a  smooth  and  polished  surface  is  not  required. 

"The  low-carbon  steel  tubing  may  be  made  from  either  hot- 
or  cold-rolled  stock.  By  far,  the  largest  amount  is  made  from 
cold-rolled  sheet  on  account  of  its  smooth  finish  and  good  ap- 
pearance. Other  metals  can  be  machine-welded  satisfactorily, 
but  where  they  are  ductile  as  in  the  case  of  brass  and  copper, 
it  may  be  cheaper  to  make  them  by  seamless  drawing. 

' '  Low-carbon  steel  us  usually  purchased  from  the  mills  in  the 
shape  of  strips  or  sheets  which  can  be  rolled  and  sheared  ac- 
curately to  the  required  dimensions.  Gang  shears  reduce  the 
sheet  to  strips  of  accurate  width  in  one  operation.  The  tubing 
is  formed  cold  by  first  rolling  it  to  semi-circular  form  and  closing 
it  in  to  the  circular  form  either  in  a  conical  drawing  die  or 
by  further  reductions  in  size  between  rolls,  the  latter  being 
generally  the  preferred  process  because  it  eliminates  subsequent 
warping  at  the  seam. 

"Kails  from  which  high-carbon  tubing  is  usually  worked  up 
are  broken  into  the  correct  lengths  to  produce  a  50-ft.  skelp, 
heated  in  an  ordinary  heating  furnace  and  broken  down  to 
rectangular  section  of  the  desired  gage  and  width  by  a  series 
of  rolls  of  the  usual  rolling-mill  type.  Thex  skelp  is  then  passed, 
while  still  hot,  through  a  pair  of  rolls  which  form  the  section 
to  a  half  circle  and  force  it  through  a  conical  die  which  draws 
in.  the  edges  to  the  final  complete  circular  section  required  for 
tubing. 

"Owing  to  the  inaccuracies  of  this  type  of  mill,  the  gage  and 


250 


GAS   TORCH  AND   THERMIT   WELDING 


width  of  the  skelp,  which  latter  dimension  determines  the 
diameter  of  the  tubing,  cannot  be  held  to  any  close  accuracy, 
and,  consequently,  this  type  of  tubing  is  used  only  for  purposes 
where  exact  size  is  not  important,  such  as  bedstead  frames, 
handles  for  tools,  and  the  like. 

"Machines  for  tube  welding  consist,  in  general,  of  a  table 
with  frame,  or  housings,  upon  which  is  mounted  the  feeding 


FIG.  209. — Feeding  End   of  Tube-Welding  Machine  With  Oxweld 
Multiple-Jet  Gas  Torch. 

mechanism  and  its  drive ;  above  this,  a  gas-torch  holder  equipped 
with  a  horizontal  adjustment  at  right  angles  to  the  seam, 
another  in  the  direction  of  the  axis  of  the  torch  and  a  hinged 
arrangement  by  which  the  torch  may  be  lifted  away  from  the 
work. 

' '  There  are  two  general  types  of  feeding  mechanism,  one  of 
which,  covered  by  the  Lloyd  patents,  consists  of  a  continuous 
or  endless-chain  arrangement.  Two  chains  are  required,  one 


WELDING   MACHINES 


251 


on  each  side  of  the  tube,  each  link  carrying  a  block  with  a 
groove  in  its  face  to  fit  the  tube.  Two  corresponding  blocks, 
when  moved  forward  between  rolls  upon  which  the  endless 
chains  are  mounted,  catch  the  tube  between  jaws  and  carry  it 


FIG.  210.— The  Left  Set  of  Eolls  Feed  the  Tubing  while  the 
Spreader  Disk  Opens  the  Seam  Slightly. 


The    central    rolls    hold    the    tubing    to 
right  set  of  rolls  act  solely  as  guides. 


specified    diameter    while    welding    and    the 


forward  at  a  uniform  rate  of  speed,  at  the  same  time  com- 
pressing the  seam  the  desired  amount  to  secure  a  satisfactory 
weld. 

' '  How  Rolls  Are  Arranged. — The  other,  and  more  generally 
used  method,  shown  in  Figs.  209,  21.0  and  211,  employs  two 
trains  of  rolls,  three  on  each  side,  having  grooved  surfaces  to 


252 


GAS  TORCH  AND  THERMIT  WELDING 


fit  the  tubing.  The  middle  pair,  known  as  the  welding  rolls, 
are  chamfered  away  on  the  top  side  to  allow  the  welding  flame 
to  work  in  between  them.  The  forward  and  rear  pairs  are 
used  merely  as  feed  and  guide  rolls.  In  order  that  different 
sizes  may  be  welded  on  the  same  machine,  rolls  having  grooves 
of  varying  depth  are  provided  to  fit  the  various  diameters  of 
tubing  to  be  welded.  Provision  is  also  made  for  opening  and 
closing  the  rolls  to  get  heavier  o>r  lighter  welds. 

"Experience  has  shown  that  to  secure  an  even  and  smooth 
seam,  it  is  necessary  to  counteract  the  effect  of  expansion  and 


REAR  ROLLS          WELD/NG  ROLLS         FORWARD  ROLLS 


ACETYLENE 


Plan 
A  £/recf/on  of  Feed 


Elev  cation  Section  A- A 

FIG.  211. — Diagram  of  Arrangement  for  Tube  Welding. 

contraction  by  spreading  the  seam  open  V32  in.,  more  or  less, 
about  6  in.  ahead  of  the  welding  rolls.  This  is  generally  accom- 
plished by  mounting  a  thin  disk  abreast  of  the  forward  guide 
rolls  at  such  a  distance  that  its  lower  edge  will  enter  and  spread 
the  seam  apart  the  necessary  amount  to  secure  this  smoothness 
of  weld.  This  disk  also  answers  the  purpose  of  aligning  the 
seam  under  the  flame. 

"The  drive  should  be  arranged  to  give  different  speeds  in 
order  that  the  machine  may  be  used  on  different  types  of  weld- 
ing, but  should  be  of  such  pattern  that  when  once  the  speed 
is  set,  it  will  remain  closely  uniform. 


WELDING   MACHINES 


253 


' '  There  are  two  general  types  of  oxy-acetylene  torches  in  use, 
corresponding  to  the  two  schools  of  oxy-acetylene  practice ; 
namely,  the  low-pressure  and  pressure  types.  The  low-pressure 
type  is  very  successful  in  welding  operations  owing  to  the 
1  softness'  of  the  flame  due  to  the  low  velocity  of  the  heating 
gases.  It  also  implies  efficiency,  as  the  gases  passing  over  the 
metal  at  a  low  velocity  have  more  time  to  give  up  their  heat. 
The  uniformity  of  the  low-pressure  flame  is  because  the  acety- 
lene is  supplied  from  a  gas  bell  at  an  even  pressure. 


FIG.  212. — Four- Jet  Type  W-5  Water-Cooled  Welding  Torch. 


FIG.  213. — Oxweld  Type  W-8  Single-Jet  Water-Cooled  Welding  Torch. 

1  i  In  the  welding  of  heavier  gages,  more  heat  is  required  than 
for  lighter  work  and  this  is  secured  by  arranging  a  variable 
number  of  flames  in  a  line  progressively  along  the  seam  to 
be  welded  (see  Fig.  212).  The  forward  flames  successively 
raise  the  temperature  of  the  tube  to  such  a  point  that  the  last 
flame  will  fuse  the  metal  just  abreast  of  the  welding  rolls  which 
compress  the  fused  edges  together,  forming  a  perfect  weld.  For 
welding  tubing  of  14  gage,  as  high  as  nine  or  ten  flames  have 
been  successfully  employed  and  with  this  number  of  flames  a 
welding  speed  of  5  ft.  per  minute  can  be  obtained.  With  such 
a  concentration  of  heat,  water-cooling  is  necessary  to  maintain 


254 


GAS   TORCH   AND   THERMIT  WELDING 


a  uniform  flame  and  eliminate  backfiring  or  ignition  of  the 
gases  within  the  tip.  The  torch  proper  is  always  water-cooled 
to  secure  uniformity  of  flame  and  for  the  comfort  of  the 
operator.  For  the  heavier  work,  mentioned  above,  the  possibilities 
range  down  to  22-  or  even  24-gage  metal,  upon  which  a  single 
flame  torch,  Fig.  213,  may  be  employed.  Short  samples  of 
welded  tubing  are  shown  in  Fig.  214. 

'  *  After  welding,  if  it  is  desired  to  secure  a  very  exact  diameter, 
either  externally  or  internally,  this  is  accomplished  by  drawing. 
The  operation  is  performed  on  the  draw  bench  which  consists 
of  a  long  frame,  usually  horizontal,  at  one  end  of  which  is  a 


il 


FIG.  214. — Samples  of  Tubing  Welded  by  the  Oxy- Acetylene 
Machine  Welding  Process. 

A — Cartridge  case.    B — Tubing  as  welded.  C  and   D — All  traces  of  welding  eliminated 
by  grinding  and  polishing.    E  and  F — Wind-shield  frame  and  wedge. 

die  of  chilled  cast  iron  or  hardened  steel.  This  die  must  be 
of  the  correct  diameter  and  smoothly  polished  to  produce  the 
correct  finish.  It  may  be  either  externally  or  internally  applied. 
When  used  on  the  inside  of  the  tubing,  it  is  known  as  a 
'triblet.'  The  tubing  is  entered  into  the  die  or  over  the 
triblet ;  the  end  is  crushed  to  secure  a  grip  for  the  drawing 
mechanism,  which  is  located  at  the  opposite  end  of  the  bench, 
and  the  tube  is  then  drawn  through  the  die  producing  the  correct 
size  and  a  very  smooth  finish.  Suitable  lubricants  must  be 
applied  to  the  surfaces  of  the  tubes  during  this  process. 

"Where  only  a  bright  finish,  without  exact  diameter,  is  re- 
quired, drawing  is  not  employed — ordinary  flashing  or  polish- 
ing methods  being  sufficient.  If  the  tubing  is  to  be  painted,  or 


WELDING   MACHINES  255 

for  some  other  reason  high  polish  is  not  necessary,  it  is  often 
satisfactory,  if  a  smooth  weld  is  secured,  to  use  the  tubing  just 
as  it  comes  from  the  welding  machine. 

"The  principal  difficulties  encountered  in  tube  welding  are  to 
secure  a  uniform,  continuous  and  neutral  flame  and  to  feed  the 
tubing  under  the  torch  at  a  correct  and  uniform  rate  of  speed 
at  the  most  effective  distance  from  the  tip  with  the  seam  exactly 
in  the  flame. 

"The  first  difficulty  is  largely  solved  by  using  the  proper 
torch.  The  second  difficulty  is  mechanical  and  can  only  be 
eliminated  by  standardizing  shop  conditions. 

"The  stock  strip  must  be  held  to  exact  width  if  a  uniform 
diameter  and  thickness  of  weld  are  to  be  produced.  The 
tolerances  are  determined  by  experience,  but  once  set  should 
be  strictly  held  to.  Burrs  on  the  sheared  edges  must  absolutely 
be  eliminated  as  these  get  into  the  seam  and  hold  it  open  causing 
'skips/  When  the  strip  is  formed  into  tubing,  care  must  be 
taken  to  secure  a  very  exact  adjustment  of  the  rolls  and  dies 
or  otherwise  the  seam  in  the  tube  will  assume  a  spiral  shape, 
causing  difficulties  in  guiding  the  seam  exactly  under  the  flame. 
If  the  flame  does  not  play  exactly  upon  the  seam,  only  one 
side  of  the  seam  will  be  fused  and  the  weld  will  'skip'  until 
the  flame  is  correctly  adjusted.  Lost  motion  in  the  feed  rolls 
and  in  the  adjusting  mechanisms  of  the  torch  holder  will  invari- 
ably aggravate  this  difficulty. 

"In  the  early  days  of  this  art,  when  manufacturers  were 
content  with  speeds  of  2  to  3  ft.  per  minute,  it  was  possible  for 
the  operator  to  adjust  his  flame  from  side  to  side,  follow  the 
irregularities  in  the  seam,  and  to  slow  down  his  machine  when 
the  weld  showed  a  tendency  to  skip.  With  the  speeds  attained 
in  modern  production,  from  two  to  four  times  as  fast  as 
formerly,  this  is  no  longer  possible.  The  operation  progresses 
so  rapidly  that  it  is  humanly  impossible  for  the  operator  to 
adjust  his  machine  to  changing  conditions  and,  in  consequence, 
if  the  seam  is  not  perfectly  true  the  operator  must  necessarily 
fail  to  get  a  continuous  weld  and  even  in  attempting  to  do  so 
he  will  constantly  slow  down  his  machine,  thus  limiting  the 
quantities  of  tubing  produced. 

"The  successful  manufacturers  have,  therefore,  applied  the 
well-known  principles  of  scientific  management  to  this  problem 


256  GAS  TORCH   AND   THERMIT  WELDING 

and  by  studying  the  conditions  under  which  the  forming  and 
welding  are  done  have  succeeded  in  so  standardizing  their 
product  that  the  welder  is  not  required  to  do  anything  but  start 
the  tube  into  the  machine  and  keep  the  torch  lit  and  the  tip 
free  from  accumulations  of  slag  and  dirt.  The  tubing  is  re- 
quired to  come  absolutely  uniform  in  diameter  and  straight  in 
seam.  The  set  of  the  rollers,  speed  of  welding  and  pressures 
of  the  gases  in  the  torch  are  adjusted  by  the  foreman  or  tool 
setter  in  charge  to  predetermined  standards  which  are  not 
allowed  to  be  changed  by  the  operator.  If,  with  the  machine 
as  delivered  to  the  operator,  he  cannot  secure  good  tubing,  the 
machine  is  shut  down,  the  trouble  discovered  and  the  proper 
remedy  applied. 

"By  the  application  of  such  methods  as  these  and  with  the 
full  cooperation  of  the  manufacturer  of  oxy-acetylene  apparatus, 
it  is  not  remarkable  that  great  progress  in  the  development  of 
the  art  of  oxy-acetylene  tube  welding  should  have  been  made 
within  so  short  a  time." 


CHAPTER  XV 
CUTTING   WITH    THE    GAS    TORCH 

The  gas-torch  cutting  process  consists  of  heating  a  spot  of 
the  metal  to  be  cut  to  a  good  red  heat  and  projecting  on  it  a 
jet  of  oxygen.  This  causes  the  metal  to  burn  away,  a  stream 
of  slag  running  out  of  the  kerf  thus  produced.  Cutting  is  not 
melting,  in  the  ordinary  sense,  although  since  the  heating  flame 
is  the  only  visible  agent,  such  might  be  the  beginner's  conclu- 
sion. It  should  be  remembered  that  the  heating  flame  is  only 
used  to  make  the  metal  hot  enough  to  oxidize  easily. 

Metals  whose  oxides  have  a  lower  melting  point  than  the 
metal  itself  can  be  cut  by  the  gas  torch.  Such  metals  are 
wrought  iron  and  steel.  Where  the  oxide  has  a  higher  melting 
point  than  the  metal,  cutting  with  the  gas  torch  is  either  im- 
possible or  not  satisfactory.  Such  metals  are  copper,  brass, 
aluminum,  cast  iron,  etc. 

A  big  factor  in  successful  cutting  is  to  properly  support  the 
body  and  torch  to  as  great  an  extent  as  possible  commensurate 
with  the  steady  forward  movement  of  the  torch.  The  position 
must  be  an  easy  one,  as  muscles  under  tension  will  cause  vibra- 
tions and  these  are  fatal  to  good  cutting.  An  ideal  position  for 
an  operator,  is  shown  in  Fig.  215,  although  in  actual,  every-day 
practice  one  usually  has  to  be  satisfied  with  less  desirable  con- 
ditions. 

Theoretically,  with  the  cut  once  started  the  oxygen  jet  alone 
should  be  sufficient  to  keep  up  the  combustion,  as  there  is  con- 
siderable heat  generated  in  the  process.  However,  the  stream 
of  oxygen  is  small  and  the  burning  metal  confined  to  a  very 
narrow  slot,  and  scale,  dirt,  sand,  blowholes  and  other  things 
interfere  to  prevent  the  continuation  of  the  cut  of  the  jet  with- 
out an  accompanying  heating  flame. 

A  cutting  torch  is  lighted  in  the  same  way  as  for  welding, 
except  allowance  must  be  made  for  the  drop  in  the  oxygen 

257 


258 


GAS  TORCH  AND  THERMIT  WELDING 


FIG.  215 An  Easy  Cutting  Position. 


FIG.  216. — Starting  a  Cut  With  a  Davis-Bonrnonville  Torch. 


CUTTING  WITH  THE  GAS  TORCH  259 

pressure  when  the  cutting  jet  is  turned  on.  This  allowance 
can  be  made  by  regulating  the  flame  while  the  jet  valve  is 
open,  which  is  done  before  starting  to  work. 

When  the  flame  is  adjusted,  hold  the  torch  as  shown  in  Fig. 
216,  the  left  hand  grasping  it  well  toward  the  head  and  the 
right  hand  on  the  handle  with  the  thumb  or  fingers  controlling 
the  jet  level  valve.  The  metal  to  be  cut  may  be  a  piece  of 


FIG.  217. — Making  a  Clean  Cut  Through  a  Plate. 

heavy  boiler  plate,  steel  bar  or  structural  steel.  Rest  the  elbow, 
forearm  or  hand  on  the  plate  to  steady  the  torch.  It  is  usually 
best  when  cutting  without  a  guide  wheel,  to  arrange  to  cut 
either  to  the  right  or  to  the  left  rather  than  toward  or  away 
from  the  operator.  However,  an  operator  should  learn  to  cut 
in  any  direction.  When  it  is  possible,  always  start  on  the 
edge.  Hold  the  flame  on  one  spot  until  it  is  a  nice  red,  then 
turn  on  the  high-pressure  oxygen  jet.  Hold  the  torch  steady 


260 


GAS  TORCH  AND  THERMIT  WELDING 


with  the  luminous  cone  almost  touching  the  metal,  until  the  cut 
goes  through.  Sparks  should  show  as  in  Fig.  217.  If  they 
fly,  as  in  Fig.  218,  the  cut  is  not  going  through. 

In  the  cutting  of  plates,  it  is  advisable  to  tip  the  torch  head 
in  the  direction  of  the  movement,  once  the  cut  has  progressed 
a  little.  This  rule  does  not  apply  in  the  case  of  blowing  holes 
in  metal  where  the  nozzle  must  be  tipped  away  from  the  slag 


FIG.  218.— Cut  Not  Going  Through  Properly. 

so  that  no  particles  will  impinge  on  the  orifices  or  a  back  pressure 
be  created  on  these  orifices. 

If  the  metal  is  very  thick,  the  oxygen  pressure  will  have 
to  be  high.  In  beginning  a  cut  of  this  type,  it  is  necessary  to 
blow  the  oxide  out  at  the  bottom  before  the  cut  has  traversed 
very  far  into  the  body  of  the  metal,  otherwise,  a  pocket  will  be 
formed  and  it  will  be  impossible  to  penetrate  to  the  bottom  of 
the  metal.  In  cutting  heavy  material,  success  depends  entirely 
upon  the  ability  of  the  individual.  The  nozzle  must  be  turned 
outward  in  preheating  and  must  be  carried  inward  with  the 


CUTTING  WITH  THE  GAS  TORCH  261 

tip  gradually  moving  to  a  vertical  position  and  finally  forward 
as  the  cut  progresses.  In  blowing  holes,  as  in  Fig.  219,  the 
metal  must  be  blown  away  from  the  tip,  and  to  accomplish  this 


FIG.  219. — Blowing  a  Hole  Through  a  Plate. 


FiG.  220. — Cutting  Off  a  Eivet  Head. 

it  is  advisable  to  begin  with  a  very  wide  kerf,  produced  by 
rapid  movement  of  the  torch  sideways  while  carried  away  from 
the  origin  of  the  cut.  In  this  way  the  oxygen  penetrates  deeper 
into  the  metal  while  the  torch  is  moving,  until,  finally,  the 


262 


GAS  TORCH  AND   THERMIT    WELDING 


oxygen  emerges  at  the  bottom,  when  the  torch  can  be  brought 
to  a  final  cutting  position  and  the  metal  cut  in  any  direction. 

Rivet  head  cutting  in  shipyards  is  generally  accomplished 
by  means  of  a  specially  designed  nozzle,  which  rests  upon  the 
plate  so  that  the  preheating  jets  and  cutting  jet  will  act  at  the 
base  of  the  rivet  head  as  shown  in  Fig.  220.  In  blowing  out 
countersunk  rivet  heads,  the  same  procedure  must  be  followed 
as  in  blowing  holes,  but  more  precautions  are  necessary  in 
order  that  particles  of  metal  do  not  impinge  on  the  preheating 
orifices  and  clog  them  or  cause  backfire. 

The  "nicking  of  billets"  became  very  common  during  the 


FIG.  221. — Using  Rollers  and  a  Bar  Guide. 

war.  A  narrow,  shallow  cut  is  made  on  one  side  or  around 
the  circumference  of  a  steel  section,  then  the  billet  is  snapped 
off  at  the  nick  in  a  press  or  hammer. 

When  a  cut  must  be  reasonably  smooth,  use  wheel  guides,  if 
possible.  If  a  straight  line  must  be  followed,  a  bar  of  metal 
may  be  clamped  to  the  work  as  shown  in  Fig.  221.  A  good 
way  to  both  guide  the  cut  and  support  the  operator's  hand, 
when  cutting  ship  plates  is  shown  in  Fig.  222.  This  principle 
may  be  applied  to  other  work. 

For  cutting  circles,  a  radius  attachment  is  used,  similar  to  the 
one  shown  in  Fig.  223,  This  device  is  macle  by  the  Carbo- 
Hydrogeii  Co.,  Pittsburgh,  Pa.,  but  practically  every  torch  manu- 
facturer makes  something  of  the  kind. 


CUTTING   WITH  THE  GAS  TORCH 


263 


The  way  the  cut  on  a  12-in.  shaft  looks  is  shown  in  Fig.  224. 
This  was  cut  with  an  Oxweld  low-pressure  torch.     The  chalked 


FlG,  222. — Cutting  Ship  Plates. 


FIG.  223. — Badius  Cutting  Attachment  for  Straight-Tip  Torch. 

arrows  indicate  a  blowhole  and  a  crack  which  materially  re- 
tarded the  cutting.  This  cut  took  3  min.  27  sec.  and  about 
75  cu.ft.  of  oxygen  was  used.  A  similar  cut,  under  similar 


264  GAS  TORCH  AND   THERMIT  WELDING 

conditions,  but  made  without  encountering  any  flaws  in  the  steel, 
was  made  in  3  min.  10  sec.  and  67  cu.ft.  of  oxygen  was  used. 

On  work  1  in.  thick  or  over,  a  slot  of  from  Vie  to  -J  in.  is 
about  right.  For  thinner  stock,  or  when  using  a  machine,  the 
slot  may  often  be  reduced  to  less  than  V16  in.  by  a  skilled  operator 
with  special  tips. 

Flame  Control. — In  working  hold  the  flame  so  that  the  end 
of  the  cone  just  clears  the  metal — do  not  attempt  to  plunge  it 


FIG.  224.— A  12-In.  Shaft  Cut  with  a  Gas  Torch. 

down  into  the  cut.  When  cutting  two  plates  or  more,  or  where 
there  is  a  lap  joint,  remember  that  there  is  more  or  less  of  an 
insulation  (air,  dirt,  etc.)  between  these  plates  and  that  the 
oxidation  cannot  be  as  fast  as  where  only  one  thickness  is  cut. 
Remember  that  the  flame  does  not  do  the  cutting — therefore, 
work  with  the  smallest  flame  possible — it  means  a  neater  cut. 
Keep  the  oxygen  pressure  as  low  as  possible  and  yet  maintain 
speed.  A  high  pressure  is  spectacular  and  there  are  a  great 
number  of  sparks,  but  it  is  not  economical  and  a  wider  kerf 
is  made.  Do  not  use  the  torch  with  greasy  gloves — a  spark 


CUTTING  WITH  THE  GAS  TORCH  265 

in  combination  with  a  leak  on  the  oxygen  supply  will  badly 
burn  the  hand.  If  a  cut  must  be  started  in  any  place  except 
on  the  edge,  drill  a  hole  or  use  a  cold  chisel  and  a  hammer 
to  roughen  up  the  surface,  the  idea  being  to  get  an  edge  to 
quickly  start  oxidation. 

Making  a  Ladle  Hook. — As  an  instance  of  the  many  savings 
that  may  be  obtained  by  the  intelligent  use  of  the  gas-torch 
cutting  process,  the  following  will  be  of  interest : 

At  one  of  the  shipyards  scrap  ship  plates  are  cut  into  special 
shapes  for  building  up  large  hooks  like  the  one  shown  in  Fig. 
225.  These  hooks  are  used  for  handling  large  ladles  in  a 
near-by  steel  mill  and  have  resulted  in  a  great  saving. 


FIG.  225. — Ladle  Hook  Made  of  Torch-Cut  Plates. 

The  hooks  are  8  ft.  in  total  length  and  are  made  up  of  six 
layers  of  plates  which  run  the  full  length,  with  four  short 
layers,  all  securely  held  together  with  countersunk  rivets.  The 
four  inner  plates  are  each  J  in.  in  thickness.  The  two  outer 
full-length  plates  are  of  f-in.  material.  Adjoining  the  latter 
plates  on  either  side  is  a  half-length  plate  J  in.  in  thickness. 
The  hook  proper  is  still  further  reinforced  by  two  slightly  shorter 
outer  plates,  each  J  in.  in  thickness. 

The  plates  are  first  marked  with  the  aid  of  a  templet  to 
serve  as  a  guide  for  the  cutting  torch.  After  cutting,  they  are 
assembled  and  riveted  as  shown  in  the  illustration.  A  laminated 
construction  of  this  sort  is  not  only  exceptionally  strong,  but 


266  GAS  TORCH  AND  THERMIT  WELDING 

is  a  decided  economy,  as  it  makes  use  of  what  would  otherwise 
be  waste  material. 

Firemen  are  frequently  confronted  with  locked  steel  doors 
or  barred  windows.  These  readily  yield  to  a  properly  applied 
cutting  torch.  Fig.  226  shows  a  fireman  demonstrating  how 
an  Oxweld  emergency  cutting  outfit  may  be  used.  The  entire 
kit  weighs  118  Ib. 

A  very  wide  field  for  the  cutting  torch  is  in  reducing  scrap 
to  workable  dimensions.  The  figures  here  given  regarding  the 
cutting  of  scrap,  are  taken  from  a  bulletin  issued  by  the  Oxweld 


FIG.  226. — Fireman  Demonstrating  an  Emergency  Kit. 

Co.  Where  costs  are  quoted  the  estimates  should  be  about 
doubled  for  present  conditions  (1920). 

An  operator  recently  cut  two  twenty-ton  steel  fire  boxes  into 
scrap,  prepared  for  the  shears  in  twelve  hours.  More  than  300 
lin.-ft.  of  cut  was  made  through  J-in.  plate  (considering  the 
mud  ring  and  over-lapping  plates).  The  total  cost  for  oxygen, 
acetylene  and  labor  was  $24.10  per  fire  box — cost  per  ton  $1.22. 

In  another  case  a  locomotive  boiler  was  cut  into  scrap  at 
a  total  cost  of  $2.63,  the  number  of  lineal  inches  cut  totaled 
210  through  |-in.  plate,  9  through  3-in.  plate  and  172  through 
f-in.  plate.  This  amount  of  cutting  was  completed  in  fifty- 
three  minutes  at  a  cost  of  8  cents  per  foot  for  the  various 
thicknesses.  The  foreman  in  charge  of  this  job  stated  that  the 
work  done  by  one  operator  in  one  and  one-half  days  would 


CUTTING  WITH  THE  GAS  TORCH  267 

require  the  services  of  two  men  for,  at  least,  a  week,  with 
ordinary  working  methods. 

A  ten-ton  boiler  was  reduced  to  scrap  ready  for  shears  by 
one  operator  in  nine  hours  at  a  total  cost  of  $16.00  or  $1.60 
per  ton. 

On  another  piece  of  work,  the  operator  cut  78  ft.  of  ^-in. 
plate  in  two  and  one-half  hours.  One  piece  of  this  plate,  18  ft. 
long,  was  cut  in  13  min.  The  cost  of  cutting  the  78  ft.  was 
$4.25  or  $0.054  per  foot  through  the  ^-in.  plate  at  a  rate  of 
over  30  ft.  per  hour. 

A  three-ton  boiler  averaged  $2  per  ton  cut  in  one  and  one- 
half  hours.  The  total  length  of  cut  equaled  60  ft.  4  in.  It 
would  have  cost  $3  to  $4  per  ton  to  cut  this  boiler  by  hand. 

A  fourteen-ton  boiler  was  cut  at  the  rate  of  $1.23  per  ton 
in  nine  hours  and  at  a  total  cost  of  $17.38.  One  hundred  and 
eleven  feet  eight  inches  of  cut  was  made  at  the  rate  of  $0.149 
per  foot. 

Three  fire-box  boilers  weighing  ten,  twelve  and  fourteen  tons 
respectively  were  scrapped  at  the  average  rate  of  $1.40  per 
ton.  The  users  of  this  plant  state  that  the  apparatus  enables 
them  to  cut  into  scrap  five  locomotives  where  one  was  handled 
by  the  methods  used  before  the  Oxweld  process  was  employed. 

Cutting  steel  car  frames  into  scrap  shows  equally  important 
savings  in  time  and  money. 

A  five-ton  car  frame  was  cut  in  two  and  one-half  hours  at 
an  average  cost  of  $2  per  ton.  It  was  cut  into  4^-ft.  lengths 
through  three  and  four  thicknesses  of  plate  in  some  parts  of 
the  frame. 

A  record  kept  of  cutting  about  12,000  Ib.  of  wrecked  steel 
car  frames  shows  a  total  cost  of  $8.10,  or  about  $1.35  per  ton. 
These  frames  were  cut  into  4|-  to  9-ft.  lengths,  in  five  hours. 

CUTTING  CAST  IRON  WITH  THE  GAS  TORCH 

In  a  paper  read  before  the  American  Welding  Society, 
April  22,  1920,  Stuart  Plumley  and  F.  J.  Napolitan,  of  the 
Davis-Bournonville  Co.,  outlined  some  of  their  experiments  in 
relation  to  the  cutting  of  cast  iron  with  a  gas  torch. 

They  said  in  part : 

While  we  are  rather  skeptical  of  the  commercial  value  of  a  cast- 
iron  cutting  torch,  and  are  convinced  that,  financially,  we  shall  never 


268  GAS  TORCH  AND  THERMIT  WELDING 

be  repaid  for  the  expense  of  our  experiments,  yet  there  are  un- 
doubtedly occasions  when  the  cutting  of  cast  iron  would  be  of  great 
value.  In  ordinary  scrap-yard  work,  it  is  so  easy  to  break  cast  iron 
that  it  would  hardly  be  economic  to  use  the  cutting  torch  as  for  steel. 

You  are  all  aware,  of  course,  of  that  application  of  oxygen  cutting 
used  largely  in  blast  furnace  practice,  the  opening  of  a  "frozen"  tap 
hole.  You  could  not  quite  reconcile  this  more  or  less  common  applica- 
tion of  the  process  with  the  pet  theory  that  cast  iron  could  not  be 
cut.  One  of  the  usual  methods  for  releasing  a  frozen  tap  hole  in  a 
blast  furnace  is  substantially  as  follows:  A  piece  of  £-in.  iron  pipe 
with  a  brass  handle  at  least  10  ft.  long  is  attached  to  a  manifold  of 
several  oxygen  cylinders.  Oxygen  is  delivered  through  this  pipe  at 
a  pressure  of  approximately  100  Ib.  per  sq.  in.  A  hole  is  started  with 
a  star  drill  or  diamond  point,  until  it  is  about  3  in.  deep.  The  metal 
adjacent  the  hole  is  heated  with  a  fuel  oil  burner  or  by  other  means. 
The  end  of  the  iron  pipe  is  ignited  and  the  composite  stream  of 
molten  iron  slag  and  oxygen  caused  to  impinge  against  the  frozen 
cast  iron. 

A  spectator  to  this  performance  of  infernal  fury,  is  readily  con- 
vinced that  the  heat  is  not  all  due  to  the  combustion  of  the  wrought 
iron  pipe,  but  that  the  cast  iron  is  burning  with  a  violence  equal  to 
that  of  steel.  This  reaction  inspired  some  inventors  to  incorporate 
a  device  in  an  oxy-acetylene  torch  for  cutting  cast  iron,  which  would 
feed  a  steel  wire  between  the  cutting  jet  and  the  cast-iron  piece  being 
cut.  Ignition  of  the  wire  carried  a  stream  of  molten  slag  on  to  the 
cast  iron  and  it  was  hoped  thus  to  propagate  the  cut.  In  a  second 
process,  a  plate  of  steel  of  a  definite  and  predetermined  thickness,  was 
placed  on  top  of  the  cast  iron.  It  was  hoped  that  the  slag  incidental 
to  the  oxidation  of  the  steel  would  exercise  some  influence  over  the 
cast  iron  and  enable  it  to  be  cut. 

Unfortunately  for  those  responsible  for  the  exploitation  of  these 
devices,  the  inventors  were  more  concerned  with  converting  cast  iron 
into  iron  oxide  by  means  of  the  oxy-acetylene  torch  than  they  were 
in  constructing  a  practical  process  and  a  practical  tool.  It  was  next 
proposed  to  simplify  the  reaction  by  supplying  an  apparatus  with  a 
mixture  of  pulverized  slag  and  iron  powder,  and  in  fact  a  number  of 
patents  were  issued  covering  various  applications  of  such  a  device. 
Crude  and  elementary  as  such  devices  were,  they  actually  produced 
combustion  of  the  cast  iron  and  went  a  long  way  in  stimulating  us 
in  our  endeavors  to  find  a  successful  method. 

Experimental  work  was  carried  on  with  a  torch  having  a  good 
many  different  tubes  leading  to  the  head  so  that  almost  any  com- 
bination of  gases  at  varied  pressures  might  be  obtained.  Mr.  Napolitan 
evolved  from  these  experiments  interesting  theories  pertaining  to  the 
reactions  which  take  place  in  cutting,  together  with  their  relation  to 
success  in  cutting  cast  iron.  He  has  noted  these  theories  in  a  separate 
paper.  We  are  presenting  these  thories  to  the  members  of  the  society 


CUTTING  WITH  THE  GAS  TORCH  269 

for  what  they  are  worth.     We  can  actually  cut  cast  iron  and  we  do 
it  by  preheating  the  oxygen. 

In  the  paper  prepared  by  Mr.  Napolitan,  he  said: 

From  the  ease  with  which  wrought  iron  is  cut  we  may  conclude 
that  an  aggregate  of  ferrite  combines  with  oxygen  with  greatest  r.vidity, 
and  permits  the  propagation  of  a  cut  with  least  interruption.  As  the 
carbon  content  is  increased,,  there  is  a  material  change  in  the  nature 
of  the  metal.  In  place  of  the  preponderance  of  ferrite  grains,  we 
recognize  the  formation  of  cementite,  and  its  union  with  some  of  the 
ferrite  to  form  pearlite — the  original  mass  of  pro-eutectoid  ferrite 
rapidly  diminishing  in  prominence.  As  we  should  anticipate  from  the 
nature  of  pearlite,  no  material  change  is  noticed  in  the  performance 
of  these  alloys  under  the  cutting  torch.  Of  course,  an  ultra-precise 
consumption  test  would  probably  indicate  a  lowering  of  the  efficiency 
coefficient,  but  from  all  appearances  no  unusual  difficulty  is  experi- 
enced in  cutting  carbon  steels  up  to  about  80  to  90  point  carbon.  But 
here,  a  definite  transition  is  indicated  by  a  distinct  laboring  of  the 
cutting  torch.  While  the  torch  will  begin  to  cut  with  practically  the 
same  effort,  and  proceeds  to  completion  without  interruption  of  un- 
usual delay,  yet  the  kerf  is  wide  and  ragged  and  undeniably  dis- 
tinguishable from  that  of  a  mild  steel  cut.  It  is  recognized  practice, 
now,  to  preheat  the  piece  to  be  cut  to  a  black  or  dull  red  heat,  when 
the  impediment,  whatever  it  was,  seems  to  have  been  entirely 
eliminated. 

But  let  metallography  explain  the  sudden  change  of  properties  of 
the  steel.  As  the  carbon  content  of  the  hyper-eutectic  steel  was  in- 
creased, the  proximate  mass  of  pearlite  increased,  and  the  pro-eutectoid 
ferrite  correspondingly  diminished  in  volume,  until  eventually  a  point 
was  reached  where  all  of  the  cementite  and  ferrite  existed  in  the 
stratified  or  laminated  relationship  of  pearlite.  This  state  is  recog- 
nized as  existing  where  the  carbon  content  is  between  80  and  90  points 
— the  approximate  analysis  of  pearlite  is  yet  undefined.  As  the  carbon 
content  is  further  increased,  there  appears  a  constituent  that  we  know 
as  pro-eutectoid  cementite — in  fancy,  the  cementite  which  has  been 
ejected  from  the  pearlite  growth.  It  is  circumstantial  that  the  presence 
of  this  pro-eutectoid  cementite  is  directly  responsible  for  the  increasing 
difficulty  of  our  cutting.  But  why  did  preheating  of  the  steel  before 
cutting  make  such  a  remarkable  difference  in  the  results?  To  be  sure, 
the  rise  in  temperature  might  affect  the  stability  of  any  martensite, 
troostite,  or  even  sorbite  that  might  have  existed,  but  the  temperature 
was  too  far  removed  from  the  Ac32i  point  to  affect  the  characteristics 
of  the  pearlite.  And  surely  the  pro-eutectoid  cementite  was  unchanged 
— and  it  was  this  same  constituent  that  we  blamed  for  the  difficulty. 

Again,  as  the  carbon  content  is  substantially  increased,  an  equivalent 
interference  with  cutting  is  apparent,  until,  when  the  carbon  content 
approaches  2.5  per  cent,  cutting  becomes  so  labored  as  practically  to 
cease,  and  no  amount  of  preheating  short  of  incipient  fusion  will 


270  GAS  TORCH  AND  THERMIT  WELDING 

permit  it  to  propagate.  As  you  are  aware,  the  metal  is  now  termed 
"cast  iron,"  and  a  micro-analysis  indicates  that  in  addition  to  the 
presence  of  a  certain  amount  of  pearlite  and  pro-eutectoid  cementite, 
as  well  as  certain  foreign  and,  to  our  discussion,  unobtrusive  sub- 
stances, we  recognize  the  presence  of  the  final  and  most  stable  state  of 
carbon-graphite.  The  pearlite  constituent  exercises  a  favorable  in- 
fluence upon  the  operation  of  cutting — and  the  pro-eutectoid  cementite, 
while  it  impedes  cutting,  is  readily  compensated  by  a  slight  preheating 
— but  the  graphite  presents  an  entirely  new*  problem. 

We  might  digress  from  the  subject  enough  to  present  some  remarks 
that  would  prove  the  fallacy  of  at  least  one  of  the  stereotyped  ex- 
planations of  why  cast  iron  cannot  be  cut — that  the  melting  point  of  the 
slag  is  appreciably  higher  than  the  melting  point  of  cast  iron. 

A  micro-analysis  of  the  structure  of  an  average  cast  iron — and  by 
average  we  refer  to  a  gray  cast  iron  of  about  three  to  four  per  cent 
carbon — would  indicate  a  structure  identical  with  that  of  a  hypothetical 
steel  of  the  same  carbon  content,  except  that  some  of  the 
carbon  seems  to  have  been  precipitated  as  graphite.  But  should 
that  identical  pour  of  cast  iron  have  been  cast  against  a  cold  iron 
mold,  or  otherwise  chilled,  the  carbon  would  not  have  been  precipitated 
as  graphite  and  we  should  have  had  what  we  shall  call  a  "chilled 
cast  iron,"  or  a  "white  cast  iron," — and  it  would  actually  have  been 
a  hyper-eutectic  steel.  Such  alloys  are  not  uncommon  in  com- 
merce, and  the  fact  that  operators  have  been  able  to  cut 
them  with  no  extraordinary  effort  has  been  responsible  for  in- 
numerable false  claims  that  cast  iron  has  been  cut.  Unfortunately, 
the  nomenclature  of  steels  and  irons  is  not  clearly  defined,  and  un- 
doubtedly a  chilled  cast  iron  is  but  an  extension  of  the  hyper-eutectic 
series.  The  melting  point  of  an  iron-carbon  alloy  is  a  constant  of 
its  composition,  whether,  in  the  solid  state,  the  metal  exists  as  a  typical 
cast  iron  or  as  a  steel.  Long  before  the  point  of  fusion,  the  carbon 
and  the  iron  exist  in  one  relationship,  that  of  austenite.  The  condi- 
tions affecting  the  pouring  of  a  melt  of  cast  iron  wrould  determine  the 
final  state  of  its  constituents —  and  we  might  as  readily  produce  a 
gray  cast  iron  or  a  chilled  wThite  cast  iron — the  carbon  as  graphite 
or  the  carbon  as  in  cementite.  In  either  event,  the  melting  points  of 
the  resulting  products  would  be  identical.  We  agree  that  chilled  cast 
iron  can  be  cut  with  comparative  ease.  It  is  evident,  then,  that  the 
melting  point  of  slag  is  not  responsible  for  the  difficulty  encountered 
in  cutting  cast  iron. 

We  had  concluded  that  \vhile  the  existence  of  pro-eutectoid  cementite 
appreciably  retarded  cutting,  the  presence  of  but  a  comparatively 
small  amount  of  graphite  completely  prevented  cutting.  The  phenome- 
non, if  it  were  true,  is  unique,  for  it  would  pre-suppose  the  incom- 
bustibility of  carbon.  Science  contradicts  us  immediately.  In  fact,  our 
own  welding  practice  belies  us.  We  might  point  to  the  reaction 
accompanying  the  removal  of  carbon  from  automotive  cylinders  by 
the  oxygen  method — or,  leaving  our  immediate  field,  we  might  mention 


CUTTING  WITH  THE  GAS  TORCH  271 

the  explosive  combustion  of  carbon  in  ordinary  gun-powder.  We  are 
forced  to  conclude  then  that,  far  from  retarding  the  combustion  of 
the  steel  matrix,  the  graphite  of  cast  iron  should  actually  assist  it. 

We  investigated  further  to  determine  how  much  graphite  influenced 
cutting.  \Ve  obtained  specimens  of  so-called  malleable  castings  of  the 
characteristic  "black  heart"  structure.  Such  a  structure  is  made  in 
this  country  by  the  annealing  of  white  cast  iron  in  which  all  of  the 
carbon  exists  in  cementite  or  pearlite,  the  latter  in  some  cases  entirely 
removed.  The  treatment  decomposes  the  cementite  to  precipitate  the 
carbon  in  minute  particles,  differing  from  the  graphite  of  gray  cast 
iron  in  their  extreme  subdivision  and  uniform  distribution  throughout 
a  ferrite  matrix.  In  making  a  black  heart  casting,  an  oxidizing  pack- 
ing is  used  in  this  country  so  that  while  the  core  is  that  of  a  black 
heart  casting,  the  mass  near  the  surface  is  ferrite.  We  removed  this 
shell  of  ferrite  so  that  our  materials  indicated,  under  the  microscope, 
a  uniform  aggregate  of  ferrite  and  temper  carbon.  By  preheating  this 
piece  to  a  dull  red  heat,  it  was  cut  with  the  characteristics  of  a  high- 
carbon  steel.  Then  we  were  satisfied  that  carbon  as  such  did  not 
prevent  cutting,  but  that  the  physical  state  of  that  carbon  was  responsi- 
ble. As  plates  of  graphite,  cutting  was  prevented ;  but  as  finely 
divided  particles,  cutting  was  scarcely  impeded. 

Reconsidering  our  previous  observations  in  the  light  of  this  de- 
velopment, we  began  to  substantiate  our  first  logical  hypothesis.  We 
found,  to  summarize,  that  ferrite  permitted  most  readily  to  be  cut. 
Pearlite  with  pro-eutectoid  ferrite  did  not  materially  affect  the  condi- 
tions. A  completely  eutectic  composition  first  suggested  a  transitory 
stage.  The  existence  of  pro-eutectoid  cementite  retarding  cutting;  but 
preheating  of  the  piece  to  a  red  heat  readjusted  the  conditions  so  that 
cutting  was  again  as  efficient  as  in  the  case  of  ferrite.  As  the  com- 
paratively low  temperature  produced  by  preheating  was  insufficient  to 
effect  any  change  in  the  physical  state  of  the  constituents  of  the 
alloy,  we  were  forced  to  conclude  that  the  addition  of  heat  units 
affected  a  definite  constant,  which  we  assumed  was  the  heat  of  com- 
bustion of  the  iron,  as  the  two  forces  were  of  like  characteristics. 
Then  a  constant  result  from  a  variable  made  axiomatic  the  existence 
of  a  second  variable.  Our  second  variable  then,  we  concluded,  was 
the  cooling  effect  of  the  stream  of  cutting  oxygen,  and  a  further 
thought  suggested  a  third  variable  in  the  time  of  chemical  reaction 
between  the  iron  and  oxygen.  The  preheating  flames  ignited  the 
steel — the  cutting  oxygen  produced  combustion — and  the  propagation 
of  the  cut  was  a  natural  consequence.  But  as  the  carbon  content  was 
increased,  the  speed  of  the  reaction  was  materially  lowered;  however, 
the  velocity  of  cutting  oxygen  to  insure  a  continuity  of  oxygen  and 
slag  to  the  bottom  of  the  cut,  was  a  constant.  Then,  eventually,  a 
point  was  reached  where  the  rate  of  combustion  between  the  iron  and 
oxygen  was  so  slow  that  the  heat  units  liberated  from  the  reaction 
were  dissipated  to  such  an  extent  as  no  longer  to  ignite  adjacent 
masses  of  metal — and  cutting  ceased.  By  preheating  the  piece  before 


272 


GAS  TORCH  AND  THERMIT  WELDING 


cutting,  we  add  to  the  forces  on  the  weakening  side  of  the  equilibrium, 
and  cutting  once  more  obtained.  The  heat  units  so  obtained  com- 
pensated for  the  relatively  less  heat  units  liberated  from  the  chemical 
combination  of  the  iron  and  oxygen  in  a  definite  unit  of  time. 

While  the  pearlite  and  pro-eutectoid  cementite  are  readily  com- 
pensated, the  graphite  carbon  effectively  prevents  cutting  by  the  ordinary 
means.  No  addition  of  heat  units  short  of  incipient  fusion,  by  pre- 
heating the  object,  restores  the  equilibrium.  We  cannot  strengthen 
further  one  side  of  our  equilibrium,  but  we  have  not  attempted  to  affect 
the  other  side.  We  had  made  no  attempt  to  reduce  the  cooling  effect 
of  the  cutting  oxygen.  We  therefore  experimented  in  this  direction, 
and  found  that  we  could  so  effectively  preheat  the  cutting  oxygen  that 
we  could  restore  the  equilibrium  without  preheating  the  object. 

In  regard  to  the  foregoing  it  will  be  of  interest  to  the 
reader  to  know  that  the  following  article  was  published  in  the 
July,  1919,  issue  of  Autogenous  Welding: 


FIG.  227. — Four  Corners  of  Large  Cast-Iron  Stone  Crusher  Head  Beveled 
with  Cutting  Torch  for  Welding. 

"  Substantial  progress  has  been  made  which  shows  that  cast 
iron  cutting  with  the  torch  is  a  practical  commercial  proposi- 
tion. Proof  is  shown  in  the  two  views  of  the  four  corners  of 
a  large  stone  crusher  head  that  were  prepared  for  welding  by 
beveling  the  edges  with  the  torch  as  shown  in  Fig.  227.  The 
job  was  accepted  in  our  welding  shop,  with  a  promise  of  com- 
pletion in  two  days,  but  it  was  found  that  a  much  longer  time 
would  be  required  alone  to  bevel  the  edges  by  chipping.  The 
Staff  of  the  Engineering  and  Research  Department  of  the  Davis- 


CUTTING  WITH  THE  GAS  TORCH  273 

Bournonville  Co.,  which  had  been  experimenting  in  cast  iron, 
was  appealed  to,  with  the  result  that  the  four  pieces  were  made 
ready  for  welding  in  less  than  one  hour ! 

"Each  corner  piece  represents  a  cut  4J  in.  thick  and  17  in. 
long,  with  an  area  of  76  sq.in.  The  cuts  were  made  in  6J 
min.  each,  using  24  cu.ft.  of  oxygen-  and-  about  4  cu.ft.  of 
acetylene.  The  cut  surface  produced  was  smooth  and  the  edges 
were  sharply  defined,  as  is  shown  in  the  views.  The  kerf  was 
about  V16-in.  wide  at  the  top  and  bottom — about  the  same  as 
would  be  produced  by  cutting  steel  of  the  same  thickness.  The 


FIG.  228— Cutting  Torch  Made  to  Preheat  the  Oxygen  Cutting  Jet. 

process  was  not  one  of  melting,  as  the  sharp  edges  prove — in 
fact  the  finish  of  the  cut  surfaces  compares  favorably  with  that 
of  steel.  After  the  cuts  were  started  they  were  carried  through 
to  completion  without  a  stop,  and  the  pieces  dropped  apart  of 
their  own  weight." 

Since  it  is  known  that  the  cutting  of  cast  iron  is  principally 
accomplished  by  preheating  the  oxygen,  attention  is  called  to 
the  fact  that  there  have  been  cutting  torches  on  the  foreign 
market  for  several  years  so  made  as  to  preheat  the  oxygen  cut- 
ting jet.  One  of  these  is  shown  in  Fig.  228,  the  principle  on 
which  it  is  made  being  self-evident. 

Another  torch  which  is  a  combination  carbon  electrode  and 


274  GAS  TORCH  AND  THERMIT  WELDING 

oxygen  jet  is  shown  in  Fig.  229.  This  was  patented  by  R.  B. 
Chapman  and  J.  W.  Kirk  in  1918.  The  construction  is  obvious 
as  the  electric  current  source  and  connections  are  shown  at  the 
left  and  the  oxygen  tank  and  tubing  at  the  right.  The  carbon 
electrode  has  a  hole  in  the  center  through  which  the  oxygen  jet 
is  projected.  As  the  temperature  of  the  arc  is  considerably 


FIG.  229.— Carbon  Electrode  and  Oxygen  Jet  Torch. 

higher  than  that  of  the  gas  torch  the  oxygen  is  highly  heated 
as  well  as  the  metal. 

OXY-HYDROGEN  CUTTING 

Elmer  H.  Smith,  secretary  of  the  Commercial  Gas  Co.,  writing 
in  the  Welding  Engineer  says: 

As  I  had  never  had  the  opportunity  to  get  an  accurate  cost  on 
oxy-hydrogen  cutting,  either  through  experience  of  others  or  through 
my  own  work  I  was  very  glad  to  take  the  data  on  a  recent  job  where 
I  could  get  absolute  facts  and  figures. 

The  work  consisted  in  splitting  a  number  of  steel  plates  13/16-in. 
thick  by  26  ft.  10  in.  long  and  was  done  by  one  of  our  spring  motor 
cutting  torch  carriers  with  our  standard  straight  line  torches  with  a 
No.  1  cutting  tip  made  especially  for  hydrogen  cutting. 

As  cutting  is  a  process  of  burning  we  convert  the  iron  to  iron  oxide 
or  Fe3O4,  which  means  that  the  burned  iron  is  composed  of  three 
parts  of  iron  and  four  parts  of  oxygen.  Since  the  atomic  weight  of 
one  part  of  iron  is  56  as  compared  to  16  for  oxygen,  this  means  that 
the  weight  of  the  oxide  would  be  composed  of  3  x  56  unit  weights  of 
iron  and  4x16  unit  weights  of  oxygen,  or  a  ratio  by  weight  of  168 
parts  of  iron  to  64  parts  of  oxygen.  In  other  words,  if  we  were  to 
take  232  Ibs.  of  slag  produced  by  cutting  it  would  contain  64  Ibs.  or 
about  700  cu.ft.  of  oxygen  and  168  Ibs.  of  iron. 

For  means  of  comparison  the  following  figures  are  set  forth,  showing 


CUTTING    WITH   THE   GAS   TORCH  275 

what  the  gas  consumption  would  be  on  this  particular  class  of  work 
if  the  cutting  was  done  with  theoretical  efficiency. 

Fe304  =  Fe  168,  O  64  (pts.  by  weight). 

26  ft.  10  in.  =  322  in. 

322  in.  —  13/16-in.  thick  =  261.6  sq.in.  of  cut. 

4  cuts  =  1046.4  sq.in. 

1046.4  sq.in.  of  cut  3/32  in.  thick  =  98.1  cu.in.  metal  removed. 

Steel  weighs  .2831  Ib.  per  cu.in. 

98.1  cu.in.  weighs  27.8  Ibs. 

Now  if  all  the  oxygen  used  had  combined  with  the  iron  to  do  the 
cutting  we  would  require  64/168  of  27.88  Ibs.  or  approx.  10.6  Ibs.  of 
oxygen.  As  1  Ib.  oxygen  equals  11.209  cu.  ft.,  the  amount  required 
theoretically  is  118.81  cu.ft.  In  actual  practice,  however,  we  cannot 
obtain  any  such  efficiency,  as  the  cutting  jet  must  be  of  sufficient 
volume  and  pressure  to  blow  out  the  slag  and  clean  the  kerf  of  oxide. 
This  means  that  an  excess  of  oxygen  must  be  used  to  do  the  more 
or  less  mechanical  part  of  the  work.  In  addition  some  oxygen  must 
be  supplied  to  combine  with  the  hydrogen  to  provide  the  heating  jet. 
None  of  this  oxygen  is  used  in  converting  the  iron  to  Fe3O4  and 
represents  a  total  loss  as  far  as  the  theoretical  figures  go. 

Of  course  if  we  expected  to  get  down  to  exact  figures  we  should 
have  an  analysis  of  the  steel  to  be  cut  and  allow  for  the  oxygen  neces- 
sary to  convert  the  carbon  and  manganese  to  oxides,  but  the  proportion 
is  so  small  as  to  be  almost  negligible. 

Now  let  us  see  what  obtains  in  actual  practice  in  machine  cutting 
of  ordinary  steel  ship  plates  free  from  rust  but  coated  with  the  usual 
amount  of  thin  mill  scale. 

I  set  up  the  motor  and  after  a  short  trial  adjusted  the  oxygen 
pressure  to  22  Ibs.  pressure  and  the  hydrogen  to  3  Ibs.  This  oxygen 
pressure  may  appear  a  trifle  high,  but  it  must  be  remembered  that  it 
was  not  only  efficiency  in  gas  that  was  desired  but  also  saving  in  time 
and  there  was  too  the  friction  of  a  25-ft.  length  of  hose  to  overcome. 
(I  have  often  cut  1-in.  steel  with  less  than  10  Ibs.  pressure.)  I  then 
adjusted  the  speed  of  the  machine  to  14  in.  per  minute  which  was 
the  maximum  speed  at  which  the  cut  would  clear  itself  perfectly.  The 
pressure  gages,  previously  tested  for  accuracy,  showed  1780  Ibs.  on  the 
oxygen  and  1800  Ibs.  on  the  hydrogen  drum.  At  the  end  of  the  run 
the  gages  showed  305  Ibs.  on  the  oxygen  and  1175  Ibs.  on  the  hydrogen. 
As  the  drums  were  200  cu.ft.  capacity  the  consumption  was  1475/9  = 
164  cu.ft.  oxygen  and  525/9  =  70  cu.ft.  of  hydrogen.  As  the  oxygen 
for  the  heating  jet  was  supplied  from  the  same  drum  and  through  the 
same  regulator  as  the  oxygen  for  the  cutting  jet  it  was  impossible  to 
determine  the  amount'  used  in  the  heating  jet,  but  I  would  estimate 
that  it  was  approximately  30  cu.ft.  as  it  was  much  more  than  is  used 
in  any  oxy-hydrogen  welding  flame.  This  would  leave  134  ft.  oxygen 
for  the  actual  cutting  operation,  which  is  but  15.19  cu.ft.  more  than 
the  theoretical  amount  required.  The  kerf  was  just  a  few  thousandths 
of  an  inch  under  3/32  in.  which  would  throw  the  balance  against  the 


276  GAS  TORCH  AND   THERMIT  WELDING 

efficiency  slightly,  but  computing  from  the  above  figures  it  is  shown 
that  the  actual  results  are  88  per  cent  of  the  theoretical  figures.  On 
account  of  the  lack  of  definite  figures  on  cost  of  cutting  with  either 
the  oxy-acetylene  or  oxy-hydrogen  process  on  actual  cutting  jobs  it 
might  not  be  amiss  to  compute  the  foregoing  figures  to  show  the 
approximate  cost  per  sq.iri.  of  cut. 

Purity  of  oxygen  99.5. 

Purity  of  hydrogen  99.8. 

1288   lineal   inches   13/16   in.   thick  =  1046.4  sq.in. 

164  cu.ft.  oxygen   @  IJc $2.46 

70  cu.ft.  hydrogen  @  Ic TO 


Total  gas  cost 3.17 

Total  oxygen  cost  per  sq.in.   cut $.00235 

Total  hydrogen  cost  per  sq.in.  cut 0007 

Total  gas  cost  per  sq.in.  cut $.00305 

Oxygen  per  line,al  ft 1.53  cu.ft. 

Hydrogen  per  lineal  ft..     .65  cu.ft. 

Total  gas  cost  per  lineal  ft.  cut $.02945 

These  figures  cannot  be  obtained  in  free-hand  cutting  and  could 
not  be  expected  as  the  cutting  jet  must  be  maintained  at  a  considerably 
higher  pressure  to  overcome  the  unsteadiness  on  the  part  of  the  operator. 
The  heating  flame  must  also  be  larger  in  free-hand  cutting,  or  the  cut 
will  frequently  be  lost  requiring  the  operator  to  turn  off  the  cutting 
jet  and  start  over. 

From  the  figures  given  me  on  the  use  of  oxy-acetylene  cutting  in 
which  the  oxygen  was  approximately  98  per  cent  pure,  the  cost  of  the 
cut  per  lineal  ft.  was  6c.  However,  I  did  not  conduct  the  test  with 
oxy-acetylene  and  am  taking  the  results  obtained  by  the  foreman  in 
charge.  He  stated  that  the  pressure  in  the  oxygen  was  35  Ibs.  and  on 
the  acetylene  8  Ibs.  The  resulting  cut  was  not  nearly  so  smooth  nor 
regular  as  that  produced  by  the.  oxy-hydrogen  and  in  addition  there 
was  an  accumulation  of  slag  at  the  bottom  of  the  cut  which  was 
entirely  absent  when  hydrogen  was  used. 

We  all  know  that  if  oxygen  is  diluted  with  a  very  small  quantity  of 
incombustible  gas,  such  as  carbon  dioxide,  its'  efficiency  is  greatly 
reduced  and  a  decrease  of  4  per  cent  in  purity  results  in  an  increased 
consumption  of  60  per  cent  in  oxygen.  But  we  may  start  out  with  a 
very  pure  oxygen  in  oxy-acetylene  cutting  and  still  have  a  high  consump- 
tion, which  would  lead  one  to  believe  that  the  oxygen  of  the  cutting 
jet  is  diluted  after  it  leaves  the  cutting  tip  with-  the  products  of  com- 
bustion of  the  heating  flame,  which  contains  carbon  monoxide,  which 
is  not  present  in  the  oxy-hydrogen  flame. 

It  was  interesting  to  note  that  when  the  heating  jet  was  adjusted 
to  heat  at  about  the  same  rate  as  oxy-acetylene  in  starting  the  cut 
the  top  of  the  kerf  was  very  slightly  melted  over  making  a  rounded 


CUTTING  WITH  THE   GAS   TORCH  277 

edge,  but  that  when  the  flame  was  so  adjusted  that  it  required  a  half 
a  minute  or  more  to  start  the  cut  the  top  edges  of  the  kerf  were 
sharp  and  square  as  they  were  at  the  hottom.  Although  with  the 
flame  adjusted  at  a  point  requiring  30  seconds  to  start  the  cut,  after 
it  was  once  started  no  trouble  was  experienced  by  losing  the  cut  and 
in  every  case  the  full  26  ft.  10  in.  was  cut  without  an  interruption, 
except  on  the  extreme  end  of  one  piece  which  had  a  thick  scale  of  rust. 

Although  it  is  seen  that  in  this  particular  case  the  consumption  of 
hydrogen  is  considerably  less  than  half  the  amount  of  oxygen,  my 
experience  has  not  been  quite  so  satisfactory  in  cutting  scrap  iron, 
that  is  scrap  boilers,  etc.,  where  there  is  more  or  less  rust  and  boiler 
scale  to  contend  with  and  also  the  frequent  interruption  of  the  cutting 
operation  in  shifting  from  one  piece  to  the  next.  In  cases- of  this 
kind  the  heating  flame  must  be  of  ample  capacity  to  penetrate  the 
scale  and  to  start  the  cut  almost  immediately.  It  is  also  the  custom 
to  have  the  torch  burn  while  moving  about  from  one  cut  to  the  next. 
This  increases  the  hydrogen  consumption  about  100  per  cent  more  or 
less  depending  on  the  operator.  The  thickness  of  the  metal  to  be  cut 
also  determines  the  proportion  of  hydrogen  used.  It  is  probably  safe 
to  say  that  the  amount  of  both  gases  used  will  be  practically  doubled. 

If  it  would  not  complicate  construction  to  the  point  of  imprac- 
ticability it  would  be  a  step  in  the  right  direction  to  make  a  cutting 
torch  with  a  valve  control  that  would  open  first  the  valve  controlling 
the  combustible  gas,  then  the  oxygen  for  heating  jet  and  lastly  the 
cutting  jet  valve. 


CHAPTER  XVI 
CUTTING   MACHINES 

"Where  close  cutting  to  a  line  or  pattern  with  a  gas  torch 
is  desired,  some  mechanical  device  must  be  provided  for  guiding 
the  torch.  A  properly  constructed  machine  saves  time,  mate- 
rial and  gas. 

The  more  common  mechanical  devices  in  use  are  for  feeding 


Fie.  230.— Cutting  a  Billet  with  an  Oxweld  Machine. 

the  torch  in  a  straight  line.  These  are  used  to  cut  bars,  bil- 
lets, boiler  plate,  armor  plate  and  the  like.  An  Oxweld 
straight-line  cutting  machine  is  shown  in  Fig.  230.  An  ordinary 
cutting  torch  is  used  in  this  case,  and  the  end  of  a  12  X  12-in. 
billet  has  just  been  cut  off.  The  feed  screw  may  be  turned  from 

278 


CUTTING   MACHINES 


279 


cither  end  by  means  of  handwheels,  and  means  are  provided 
for  cross  adjustment. 

Another  device,  made  by  the  Davis-Bournonville  Co.,  is  shown 
in  Pig.  231.  The  pieces,  which  were  cut  the  long  way,  measured 
15  X  13J  in.  This  machine  has  a  handwheel  on  one  end  of  the 
feed  screw  and  a  cone  pulley,  for  power  drive,  on  the  other. 
Unlike  the  device  first  shown  this  one  is  not  mounted  on  legs 
but  has  a  short  section  of  I-beam  for  a  base.  On  this  account 


FIG.  231. — Another  Straight-Line  Cutting  Machine. 


it  may  be  placed  on  the  object  to  be  cut  or  laid  on  blocks  or 
horses,  as  occasion  demands. 

The  device  shown  in  Fig.  232  differs  from  either  of  the 
foregoing  in  that  racks  are  used  in  place  of  lead  screws.  This 
is  made  by  the  Great  Western  Cutting  and  Welding  Co.,  San 
Francisco,  Cal.  The  heavy  structural  iron  base  is  so  made  that 
it  may  be  placed  on  the  work,  laid  on  blocks  or  horses  or  mounted 
on  legs.  Means  are  provided  for  adjusting  the  torch  up  or 
down  or  at  an  angle. 

Any  of  these  machines  may  be  used  for  cutting  out  marked 
square,  rectangular,  round  or  irregular  shaped  holes.  Where 


280 


GAS  TORCH  AND   THERMIT  WELDING 


the  metal  is  thick,  it  is  often  better,  especially  on  repetition  work, 
to  drill  a  hole  through  for  starting. 

The  Radiagraph.— The  Radiagraph  shown  in  Fig.  233  is 
made  by  the  Davis-Bournonville  Co.  It  is  a  motor-driven  device, 
with  oxy-acetylene  or  oxy-hydrogen  cutting  torch,  adapted  to 
cutting  along  straight  lines  or  circles  in  steel  plate  from  |  in. 
to  18  or  20  in.  in  thickness,  the  speeds  varying  from  2  in.  to  18 
in.  per  minute,  according  to  the  thickness  of  the  plate.  For 


FIG.  232. — Portable  Cutting  Machine  with  Rack  Feeds 

straight  line  cutting,  it  operates  upon  a  parallel  track,  and  for 
circle  cutting,  with  a  rod  and  adjustable  center.  The  device 
consists  principally  of  a  three-wheeled  carriage  driven  by  an 
electric  motor  attached  to  the  carriage,  which  may  be  connected 
to  the  ordinary  lighting  or  power  circuit,  either  d.c.  or  a.c., 
110-  or  220-volt  circuit.  An  adjustable  arm  and  torch  holder 
provides  for  raising  or  lowering  the  torch  while  in  operation, 
and  for  adjustment  at  an  angle  for  bevel  cutting.  The  adjust- 
able arm  also  permits  of  following  an  irregular  line  within  a 


CUTTING  MACHINES 


281 


FIG.  233. — Davis-Bournoiiville  Radiagrapk 


FIG.  234. — Radiagraph  Cutting  Steel  Plate  at  the  New  York 
Shipbuilding  Yards. 


282  GAS  TORCH  AND   THERMIT  WELDING 

variation  of  3  in.  on  either  side  of  a  straight  line.  The  cutting 
torch  is  connected  by  hose  to  the  gas  supply.  The  machine  is 
portable,  weighing  approximately  50  Ib.  complete,  and  has  proven 
an  invaluable  aid  in  steel  cutting,  greatly  facilitating  such  work 
in  shipyards  and  steel  mills,  several  machines  being  employed 
advantageously  in  some  of  the  larger  plants. 

An  example  of  some  of  the  straight  line  cutting  done  by  the 
Radiagraph  is  shown  in  Fig.   234.     Here  the  track  has  been 


FIG.  235. — Davia-Bournonville  Railograph. 

laid  on  a  heavy  piece  of  ship  plate  and  the  torch  is  fed  along 
at  a  uniform  rate  by  the  motor. 

The  Railograph. — For  cutting  railway  rails  the  device  shown 
in  Fig.  235  is  used.  This  is  clamped  to  the  rail  while  it  is  in 
position  on  the  roadbead  if  desired.  The  cutting  torch  may  be 
mounted  in  a  holder  on  either  side  of  the  rail.  Each  holder 
is  carried  by  a  slide.  Attached  to  each  holder  is  a  roller  which 
runs  in  contact  with  a  cam  formed  in  such  a  way  that  it  pro- 
vides for  maintaining  the  tip  of  the  cutting  torch  at  a  uniform 
distance  of  about  -J  in.  from  the  surface  of  the  work  as  the  torch 
is  fed  around  the  rail.  Feeding  of  the  torches  is  accomplished 
by  two  handwheels  which  transmit  motion  through  a  set  of 


CUTTING   MACHINES  283 

suitable  gearing.  In  operation  the  torch  is  first  applied  at  one 
side  of  the  rail  and  fed  over  the  line  on  which  the  cut  is  to  be 
made,  one-half  of  the  base  and  head  of  the  rail  and  the  web 
being  cut  in  this  way.  The  torch  is  next  removed  from  the 
holder  and  mounted  at  the  opposite  side  of  the  rail,  where  it  is 
again  passed  over  the  line  of  cut,  with  the  result  that  the  remain- 
ing half  of  the  base  and  head  of  the  rail  is  severed.  A  9-in. 
traction  rail  can  be  cut  off  in  about  three  minutes. 


FIG.  236. — Cutting  Heavy  Plate  at  the  Schneider  Works,  Creusot,  France. 

The  cutting  of  heavy  steel  plate  in  the  great  Schneider 
Works,  Creusot,  France,  is  shown  in  Fig.  236.  The  portable 
devices  are  very  similar  to  those  used  in  the  United  States. 
In  the  background  is  a  huge  machine  so  made  that  it  can  be 
used  to  trim  ends,  square  up  a  plate  and  cut  angles  or  circles. 
The  torch  carriage  is  fed  along  by  a  lead  screw  run  by  a  motor 
seen  at  the  extreme  right.  A  motor-operated  device  will  raise 


284 


GAS  TORCH  AND   THERMIT  WELDING 


or  lower  the  frame  or  give  it  a  circular  movement.  The  plates 
to  be  cut  are  run  into  position  on  small  flat  cars. 

Circular  Cutting. — Tlie  Radiagraph  cutting  circles,  is  shown 
in  Fig.  237.  The  work  was  2J  in.  thick  and  was  cut  at  the  rate 
of  6  in.  per  minute.  Note  the  true  circle  and  surface  of  the 
cut.  The  pieces  were  for  a  special  type  of  heater  for  the  Gov- 
ernment. The  round  piece,  or  flue  sheet,  is  30  in.  in  diameter 
and  the  ring,  or  flange,  45  in.  outside  diameter. 

Another  device  is  the  Holograph,  shown  in  Fig.  238.     It 


FIG.  237. — Radiograph  Used  for  Circular  Work. 

is  a  device  for  cutting  holes  in  the  web  of  a  rail,  or  in  struc- 
tural iron,  of  not  more  than  f  in.  thick.  It  is  quickly  attached 
and  accurately  adjusted.  It  pierces  through  the  iron  almost 
instantly,  without  any  previous  drilling,  and  will  cut  smooth 
round  holes  from  1  to  2  in.  in  diameter  in  from  30  to  60  sec. 
It  is  particularly  adapted  for  railroad  work,  and  enlarging  or 
cutting  holes  in  building  and  bridge  work. 

The  Magnetograph. — The  Magneto  graph  shown  in  Fig.  239 
was  designed  for  mechanically  cutting  circles  up  to  12  in. 
diameter  in  steel  plate  in  perpendicular  position,  such  as  cut- 


CUTTING    MACHINES 


285 


ting  port  holes  in  the  side  plates  of  ships.     Steel  plate  from 
J  in.  up  to  several  inches  thick  is  cut  quickly,  with  a  finished 


FIG.  238. — Davis-Bournonville  Holograph. 


FIG.  239. — Davis-Bournonville  Magnetograph. 

and  true  surface,  the  movement  of  the  oxy-aeetylene  or  oxy- 
hydrogen  torch  and  flame  being  given  by  handwheel  and  gears. 


286 


GAS   TORCH   AND   THERMIT  WELDING 


Cutting  is  accomplished  at  varying  speeds  according  to  thick- 
ness of  plate,  from  3  in.  up  to  20  in.  per  minute,  or  even  faster 
on  light  plate.  The  device  is  constructed  as  much  as  practical 
of  aluminum  to  obtain  lightness,  and  is  held  firmly  on  the  plate 
by  means  of  three  electromagnets,  connected  by  wire  to  an 
electric  circuit  (direct  current)  or  to  battery. 

The  Camograph.— The  Camograph,  Fig.  240,  is  an  adapta- 
tion of  the  Holograph.  It  is  of  the  same  general  construction, 
except  that  it  is  larger  and  ha^  a  wider  range  of  work.  It 
is  fitted  with  a  cam  for  each  particular  kind  of  work,  and 


FIG.  240. — The  Camograph. 

will  cut  almost  any  form  desired,  within  the  capacity  of  the 
machine.  This  machine  requires  special  cams  for  each 
operation. 

The  Camograph  No.  2,  shown  in  Fig.  241,  is  a  later  develop- 
ment of  the  Davis-Bournonville  Co.  It  is  automatic  in  opera- 
tion and  is  used  for  cutting  openings  in  steel  plates  that  cannot 
be  done  conveniently  or  economically  on  a  drilling  machine. 
The  torch  is  mechanically  traversed  over  a  fixed  path  and  at 
a  predetermined  speed.  The  path  followed  is  controlled  by 
an  internal  cam  at  the  top  of  the  machine,  the  shape  of  which 
determines  the  shape  of  the  opening  being  made,  the  double- 
jointed  radial  arm  permitting  universal  movement  of  the  flame 


CUTTING   MACHINES 


287 


which  perforates  the  steel.  The  principle  of  the  cam  guiding 
action  is  unique.  The  feed  roller  is  magnetized  by  a  powerful 
electromagnet,  and  is  thus  attracted  to  the  inner  face  of  the 
cam,  the  parts  in  contact  being  made  poles  of  the  magnet,  one 
of  which  rotates  and  thus  acts  as  a  traction  driver.  The  roller 
is  driven  by  a  small  variable-speed  motor  through  double  worm 


PIG.  241. — Camograph  No.  2. 

gearing,  the  magnetic  attraction  being  sufficient  to  cause  it 
to  travel  along  the  face  of  the  cam  in  a  positive  manner. 
Direct  current  is  required  owing  to  the  magnetic  feature,  and 
the  control  consists  of  a  double  push-button  switch  for  starting, 
stopping  and  also  for  energizing  the  magnet.  Arrangement  is 
provided  whereby  when  the  cutting  oxygen  is  turned  on  the 
feed  motion  automatically  starts.  The  nominal  diameter  of 


288 


GAS   TORCH  AND   THERMIT  WELDING 


the  largest  hole  cut  is  7  in.,  but  openings  other  than  circular, 
having  one  dimension  much  larger,  may  be  provided  for.  All 
thicknesses  of  plate  used  on  the  largest  marine  boilers  are 
readily  cut  with  this  machine.  The  machine  is  17  in.  wide, 
15  in.  deep,  25  in.  high,  weighs  125  lb.,  and  uses  110  volt, 
direct  current. 

The  Great  Western  Cutter. — The  machine  shown  in  Fig. 
242  is  made  by  the  Great  Western  Cutting  and  Welding  Co. 





FIG.  242. — Great  Western  Cutter. 

It  is  designed  to  cut  round,  square  or  oval  holes.  Three 
master  plates  are  furnished  for  holes  of  these  shapes.  By 
turning  the  handle  the  torch  travels  around  the  inside  of  the 
form,  to  which  it  is  held  by  the  two  coiled  springs  shown.  The 
machine  is  simple  and  light.  Extensions  are  furnished  for 
cutting  large  holes.  For  odd-shaped  holes  extra  plates  are 
required.  This  machine  is  especially  adapted  for  boiler  shops, 
shipyards,  etc.,  in  cutting  hand  holes,  manholes,  fire-box  door 
holes,  and  holes  in  tube  sheets. 


CUTTING   MACHINES]  289 

The  machine  shown  in  Fig.  243  is  known  as  the  Pyrograph 
and  is  made  by  the  Davis-Bournonville  Co.  The  model  shown 
is  not  the  latest,  but  well  illustrates  the  general  principles  of 
the  more  improved  ones.  It  was  designed  primarily  for  boiler- 
shop  use  in  turning  flanged  boiler  heads  or  cutting  openings 
for  doors,  manholes  and  the  like.  In  one  shipyard  boiler  plant, 
flanged  combustion  chamber  heads,  J  in.  thick  with  a  flange 
periphery  of  27  ft.,  were  trimmed  and  beveled  to  the  calking 
angle  in  30  min.,  exclusive  of  the  setting  up. 


FIG.   243. — Pyrograph   Trimming  and  Beveling  Boiler  Flanges. 

As  can  be  seen,  the  Pyrograph  comprises  a  motor-driven 
carriage  supported  on  a  radial  arm  of  a  length  that  provides 
for  cutting  the  flange  of  a  9-ft.  diameter  boiler  head  at  one 
setting.  "While  the  largest  diameter  circle  that  can  be  cut 
at  one  setting  is  9  ft.,  much  larger  work  may  be  trimmed  and 
beveled,  inasmuch  as  the  arm  can  be  swung  through  a  semi- 
circle of  20  ft.  or  a  full  circle  of  20  ft.  diameter,  provided 
the  shop  conditions  permit  the  arm  to  swing  in  a  complete 
circle.  Heads  larger  than  9  ft.  diameter  are  reset  as  many 
times  as  may  be  found  necessary  to  reach  the  flange  all  around. 

The  radial  arm  construction  is  light  but  rigid,  consisting 


290 


GAS  TORCH  AND  THERMIT  WELDING 


of  two  cold-rolled  parallel  round  steel  bars  firmly  tied  together 
by  end  connections  and  intermediate  spacer  blocks,  and  sup- 
ported by  a  truss  rod.  The  vertical  cast-iron  pivot  member 
of  the  radial  arm  is  mounted  on  ball  bearings  at  the  top  and 
bottom,  in  order  to  insure  the  maximum  ease  of  movement. 
The  steel  post  around  which  the  radial  arm  swings  is  adjustable 
vertically  by  means  of  a  crank  operating  a  rack-and-pinion 
gear.  A  dog  and  rachet  hold  the  post  at  any  height  within 
the  limits  of  adjustment  required. 

The  column  has  a  broad  flanged  base  which  may  be  bolted 


FIG.  244. — Details  of  Pyrograph  Feed  Mechanism. 

to  a  cast-iron  floor  plate  or  a  concrete  foundation  if  required 
to  be  self-supporting,  or  the  top  of  the  post  may  be  shackled 
to  a  column  of  the  shop  building  and  the  base  supported  on 
an  ordinary  floor  without  an  individual  foundation. 

The  carriage  is  supported  on  the  radial  arm  by  four  grooved 
ball  bearing  rollers  which  provide  for  the  easy  radial  move- 
ment required  to  follow  the  feed  action  freely.  The  carriage 
and  the  arm  derive  their  movements  from  the  feeding 
mechanism  which  operates  directly  on  the  part  to  be  beveled, 
the  flange  part  itself  acting  as  the  track  and  guide  for  the 
feeding  mechanism,  as  shown  in  Fig.  244. 


CUTTING   MACHINES  291 

The  torch  is  adjustably  mounted  on  the  carriage  beneath 
the  radial  arm,  and  the  tip  may  be  directed  at  any  angle 
required  to  cut  to  the  desired  calking  angle. 

The  flange  to  be  trimmed  and  beveled  is  gripped  between 
the  three  feeding  rollers,  two  of  which  are  small  idlers  on  the 
side  next  to  the  torch  while  the  driving  roller,  considerably 
larger,  is  located  on  the  far  side  of  the  flange.  The  driving 
feed  roller  derives  its  motion  from  a  small  electric  motor 
mounted  on  top  of  the  carriage  and  driving  through  a  reducing 
train  of  worm  and  bevel  gears.  Variations  of  speed  are  pro- 
vided by  making  the  upper  worm  and  worm  gear  replaceable 
with  worm  gears  of  different  ratios.  The  following  speeds  are 
available:  12  in.  in  70  sec.,  12  in.  in  90  sec.  and  11  in.  in 
60  sec. 

The  pressure  on  the  feed  rollers  required  to  produce  the 
traction  necessary  to  traverse  the  torch  and  carriage  is  obtained 
from  the  weight  of  the  torch,  the  slide  rests  on  which  it  is 
carried  and  the  frame  to  which  the  two  idler  feed  rollers  are 
attached.  The  frame  carrying  the  slide  rests  and  idler  feed 
rollers  is  pivoted,  and  the  weight  forces  the  idler  feed  rollers 
against  the  side  opposite  the  driving  roller  with  sufficient 
pressure  to  traverse  the  carriage  positively.  The  feed  mechan- 
ism operates  on  any  shape  whether  straight  or  curved,  thick 
or  thin.  Flanged  sheets  are  generally  rough,  presenting  a  more 
or  less  irregular  contour,  but  this  does  not  interfere  with  the 
carriage  traverse  and  the  torch  action.  The  operator  may 
interrupt  the  feed  at  any  point  by  raising  the  frame,  thus 
relieving  the  pressure  on  the  feed  roller. 

The  driving  roller  and  its  shaft  are  protected  by  a  shield 
of  fireproof  composition  having  a  beveled  flange  at  the  bottom, 
on  which  the  sparks  and  slag  have  no  effect.  The  machine, 
once  set,  trims  a  flanged  sheet  evenly  all  around,  provided 
the  sheet  has  been  properly  leveled.  Otherwise  it  is  necessary 
to  chalk  a  line  to  be  followed. 

In  the  plant  of  the  New  York  Shipbuilding  Corporation, 
three  different  combustible  gases  are  used  in  cutting  torches, 
namely,  carbo-hydrogen,  acetylene,  and  hydrogen.  The  com- 
bustible gas  selected  for  different  classes  of  work  depends  upon 
the  thickness  of  the  plates  which  have  to  be  cut.  The  range 
of  thickness  handled  by  the  different  gases  is  as  follows:  Up 


292 


GAS  TORCH   AND  THERMIT  WELDING 


to  3  in.,  car  bo-hydro  gen ;  3  in.  to  6  in.,  acetylene;  and  over 
6  in.,  hydrogen.  It  will,  of  course,  be  understood  that  either 
of  these  gases  is  mixed  with  oxygen. 

A  Universal  Cutter. — A  machine  built  somewhat  along  the 
lines  of  the  Pyrograph,  but  a  much  more  universal  machine, 
has  been  developed  for  use  in  the  shops  of  the  General  Electric 
Co.,  Schenectady,  N.  Y.  This  machine  is  shown  in  Fig.  245. 
It  can  be  set  for  automatically  making  circular,  spiral,  radial 
or  tangential  cuts.  Its  rate  of  feed  can  be  varied  from  1  to 
72  in.  per  minute,  according  to  the  character  and  thickness 
of  the  metal.  The  base  of  the  machine  is  provided  with  a 


FIG.  245. — Automatic  Universal  Cutting  Machine. 

powerful  electro-magnet  to  be  used  if  the  machine  is  placed 
on  a  rough  or  uneven  surface  and  also  to  hold  it  in  position 
when  it  is  necessary  to  perform  cutting  operations  on  work 
held  in  a  vertical  plane.  Ordinarily,  the  weight  of  the  machine 
is  sufficient  to  hold  it  steady.  As  shown,  the  machine  is  mounted 
on  a  truck  for  easy  transportation,  as  it  weighs  1,900  Ib. 

The  Oxygraph.— With  the  Oxygraph,  steel  plate  from  1  in. 
to  15  in.  or  more  in  thickness  is  cleanly  cut  with  a  narrow, 
smooth  kerf,  along  straight  lines,  sharp  angles,  or  curves, 
according  to  drawing  or  pattern.  The  pantagraph  principle 
is  employed,  with  a  motor-propelled  tracing  wheel,  with  which 
the  lines  of  the  drawing  are  followed  and  reproduced  with 


CUTTING   MACHINE? 


293 


the  cutting  torch.  Either  the  oxy-acetylene  or  the  oxy- 
hydrogen  cutting  flame  is  used,  with  hose  connection  to  the 
source  of  gas  supply.  The  only  power  required  is  for  revolving 


FIG.  246. — Single-Torch  Oxy  graph. 


FIG.  247. — Oxygraph  with  Two  Torches. 

the  tracing  wheel,  and  this  is  supplied  by  a  small  motor  attached 
to  the  tracing  head,  which  may  be  connected  to  the  ordinary 
electric  light  or  power  circuit.  A  universal  motor,  either  d.c. 
or  a.c.,  110-  or  220-volt  circuit,  with  rheostat  and  friction 


294 


GAS  TORCH  AND   THERMIT  WELDING 


governor  is  used.  The  speed  of  cutting  varies  from  2  to  18  in. 
per  minute,  according  to  the  thickness  of  steel  being  cut. 

One  size  of  machine  is  applicable  to  small  work  and  die 
cutting,  within  a  cutting  area  of  16  in.  square,  a  circle  of  18 
in.,  or  a  rectangular  form  12X40  in.  may  be  cut  by  extension 
of  the  tracing  table.  With  this  machine,  a  drawing  or  pattern 
double  the  size  of  the  cut  to  be  made  is  required,  the  drawing 
being  placed  on  the  tracing  table  shown  at  the  right  in  Fig.  246. 

Another  machine  is  made  for  larger,  heavier  work.  It  has 
a  double  pantagraph  frame  and  is  fitted  with  two  cutting 
torches  for  making  duplicate  cuts  at  the  same  time,  the  position 


FIG.  248. — Cutting  Out  a  Large  Slot. 

of  the  torches  and  tracing  wheel  being  adjustable.  The  entire 
pantagraph  frame  may  be  moved  backward  from  the  table 
to  allow  placing  of  heavy  plate  with  a  shop  crane.  This 
machine  reproduces  the  cut  of  equal  size  with  the  pattern, 
or  1  to  1. 

A  machine  with  two  pieces  of  work  and  pattern  in  place 
is  shown  in  Fig.  247. 

Another  practical  application  of  the  Oxygraph  is  shown 
in  Fig.  248.  The  piece  worked  on  is  a  fishing  tool  used  for 
fishing  out  broken  tubes  in  oil  wells.  This  Oxygraph  has  a 
bed  frame  30  in.  wide  by  9  ft.  long.  The  fishing  tool  is  hollow, 
with  walls  2-J  in.  thick,  and  weighs  900  Ib.  The  total  cut  made 
of  21  lin.  ft.  was  made  in  21  min.  or  1  ft.  per  minute. 


CHAPTER   XVII 

WELDING    SHOP    LAYOUT,    EQUIPMENT    AND    WORK 

COSTS 

The  layout  and  equipment  of  a  welding  shop  will,  of  course, 
vary  with  the  class  and  amount  of  work  handled,  the  capital 
available,  and  the  personal  opinions  of  the  owner.  One  should, 
however,  have  enough  equipment  of  a  mechanical  nature  to 
insure  the  finishing  of  work  in  a  reasonable  time  without  too 
great  an  expense  for  labor.  A  first  class  workman  can,  when 
necessary,  turn  out  a  good  job  of  difficult  work  with  a  single 
welding  and  cutting  outfit;  means  for  preheating  which  may 
consist  of  a  few  firebrick,  asbestos  and  charcoal;  a  chisel  or 
two ;  a  good  hammer  and  a  few  files.  These  are  insufficient, 
however,  where  any  amount  or  variety  of  work  is  to  be  handled 
economically  and  to  the  satisfaction  of  the  ordinary  run  of 
patrons.  A  minimum  amount  of  mechanical  equipment  should 
include  a  number  of  hand  and  handled  chisels,  several  ham- 
mers and  sledges  of  different  weights,  a  portable  electric 
grinder  or  at  least  a  grinding  stand,  and  a  portable  electric 
or  a  stationary  drilling  machine,  or  both.  To  this,  for  more 
extensive  work  should  be  added  a  pneumatic  or  an  electric 
chipping  hammer,  a  lathe,  cranes,  and  possibly  a  portable  or 
a  stationary  motor-cylinder  grinding  machine.  Oil-  or  gas- 
burning  preheaters  are  also  almost  a  necessity  in  any  case, 
while  a  gas-burning  preheater  of  the  table  type,  will  save  an 
enormous  amount  of  time  and  trouble  on  the  general  run  of 
gasoline  motor  work.  Special  grated  iron  welding  tables,  heavy 
surface  plates  and  grids,  iron  blocks  and  straps  and  numerous 
other  articles  will  need  to  be  added  as  local  requirements 
dictate. 

The  shop  layout  for  equipment  will  have  to  conform  to  the 
building  unless  the  shop  is  built  purposely  for  the  work.  In 
this  connection  very  few  suggestions  of  any  value  can  be  made, 

295 


296 


GAS  TORCH  AND  THERMIT  WELDING 


except  that  the  shop  manager  should  endeavor  to  so  place  his 
equipment  as  to  cause  the  least  running  back  and  forth  possible. 
We  will,  for  the  benefit  of  our  readers  give  the  layout  of 
a  large  shop  doing  nothing  but  welding  work.  This  is  the 
shop  of  the  Oxweld  Acetylene  Co.,  Newark,  N.  J.,  and  it  was 
built  expressly  for  this  work.  Allowance  in  position  had  to 
be  made  for  the  set  directions  of  the  railroad  and  street  lines. 


FIG.  249.— Exterior  View  of  Oxweld  Shop,  Showing  Crane  Hoists. 

Fig.  249  shows  the  end  of  the  building  next  to  the  railroad. 
The  overhead  track  for  the  chain  blocks  is  so  placed  as  to 
be  readily  used  for  loading  or  unloading  either  cars  or  trucks. 
This  is  good,  but  a  still  better  arrangement  would  be  to  extend 
the  runway  on  into  the  shop  itself  and  so  save  considerable 
rehandling  in  order  to  get  the  work  to  or  from  the  welding 
floor.  Fig.  250  is  a  floor  plan  showing  the  location  of  the 
various  benches,  lockers,  machines,  etc. 


WELDING  SHOP  LAYOUT 

Alipunoj 


297 


298 


GAS  TORCH  AND  THERMIT  WELDING 


WELDING  SHOP  LAYOUT 


299 


300 


GAS  TORCH  AND  THERMIT  WELDING 


-z 

I 

to 

a 

c 

x 
* 


WELDING  SHOP  LAYOUT 


301 


In  Fig.  251  is  shown  a  view  of  the  shop  just  inside  the 
northern  end.     The   doors  shown  at  the  right  are  the  ones 

WORKING  ORDER— WELDING  SHOP 


DATE 


NAME 

ADDRESS.. 


DESCRIPTION   OF    WO RK~  REQUIRED , _ _._ 


TIME  JOB  RATE  S 

CONTRACT  PRICE  S 

PAY  COMMISSION  OF 


__ PER  HOUR.  GAS.  MATERIAL  AND  EXPENSES  EXTRA.        INVOICE  S 

__ __  SALESMAN.   

g,  ON  S : _...._ AMT.  OF  COMMISSION   $ 

DATE   COM.   REPORTED _ 


SHOP     TRANSIT 

GAS 

LABOR 

ARTICLE 

AMOUNTS  USED 

TOTAL 

TOTAL  COST 

Cu.    FT. 

CMAI.COAL  . 











OIL 

PHtHKATING 



CAST  IKON 



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ALUM.    5/JSi'"" 









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•  •Alt 

FLUX 

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INDIRECT  CHA 
TOTAL    LAB 
OVER    HEAT 

M 
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C  A/C  rof 

"*•*-- 

GLOVM  
Goeoi.cs 







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AMT.          P»,e.             TOTAL 

BOAKO  AND 



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f 

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S  

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KXP«» 

SHOP  TRAN 
BASE    COST 
COM.    TO    S 
PROFIT    FOF 
CHARGE  CU 

SIT  - 

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ILESMAN  _~  S  -.. 
I    COMPANY  ,  »..  
STOMER..™..........._....._  ~....r.  S  

TOTAL   COST-SHOP    TRANSIT     » 

MIMARK*: 

FIG.  254. — Cost  Keeping  Form. 

that  open  out  under  the  crane  shown  in  Fig.  249.    This  interior 
view  in  Fig.  251  gives  a  good  idea  of  the  lighting  and  the 


302  GAS   TORCH  AND   THERMIT  WELDING 

ventilators  at  the  top  for  carrying  away  the  fumes.  The  air 
and  acetylene  pipe  lines  are  shown,  and  in  the  left  foreground 
is  illustrated  in  the  way  cylinders  are  chained.  In  the  central 
foreground  one  of  the  workmen  is  chipping  a  casting  with  a 
pneumatic  chisel. 

The  opposite  end  of  the  shop  is  shown  in  Fig.  252.  Here 
a  portable  crane  is  shown  in  the  middle  foreground.  Suspended 
from  it  is  a  portable  electric  grinding  machine.  Just  back  of 
this  is  an  electric  grinding  stand.  At  the  right,  in  the  back- 
ground, is  a  Wiederwax  preheater  and  just  in  front  of  this 
is  an  iron  preheating  and  welding  stand  with  an  operator  at 
work  at  it. 

At  the  left  in  Fig.  253  is  shown  a  number  of  welding  tables 
with  grated  cast-iron  tops  and  welded  angle-  and  strap-iron 
legs.  Both  the  daylight  and  artificial  lighting  are  excellent 
throughout  the  shop.  Probably  no  other  shop  would  be  built 
exactly  like  this,  as  conditions  differ  so  radically,  but  a  careful 
study  will  reveal  to  the  prospective  shop  man  some  of  the 
things  that  will,  or  will  not,  apply  to  his  particular  case. 

Keeping  Track  of  Costs. — No  shop  can  succeed  financially 
without  keeping  a  close  watch  on  cost  of  material,  gas,  labor, 
overhead,  etc.  The  way  this  is  done  in  the  Oxweld  shop  will 
be  seen  by  referring  to  the  form  shown  in  Fig.  254.  This  is 
so  made  as  to  cover  both  inside  and  outside  jobs.  These  forms 
are  made  in  duplicate  on  white  and  pink  paper,  so  that  a 
carbon  of  the  original  is  made.  These  forms  are  for  shop  and 
office  use  only,  and  from  them  the  customer's  bill  is  easily 
made  out.  With  forms  of  this  kind,  the  entire  data  relating 
to  any  job  may  be  had  at  any  time  by  reference  to  the  files. 

Another  form  of  cost  card,  suggested  by  the  Imperial  Brass 
Manufacturing  Co.,  is  shown  in  Fig.  255.  This  is  not  so  com- 
plicated as  the  form  just  given,  and  will  answer  in  many  cases. 
The  manager  should  not  forget,  however,  to  add  to  this  the 
cost  of  overhead,  which  it  is  wise  to  make  fairly  high  to  allow 
for  contingencies — say  from  100  to  150  per  cent. 

Carbon  Burning. — While  carbon  burning  has  nothing  to  do 
with  welding,  the  ordinary  welding  shop  is  often  called  upon 
to  do  such  work  on  account  of  having  a  supply  of  oxygen 
at  hand. 

Carbon  in   a  motor  cylinder  is   caused  by   imperfect   com- 


WELDING  SHOP  LAYOUT  303 

bustion.  It  may  be  that  the  carburetor  was  not  adjusted  so 
as  to  give  sufficient  air,  or  it  may  be  too  much  oil  was  used. 
The  use  of  oxygen  is  the  most  practical  and  thorough  way 
to  remove  this  deposit. 


Oxygen  gage,  start 1800  Ibs.— 100  cu.  ft. 

Oxygen  gage,  finish 900  lbs.=  50  cu.  ft. 

Oxygen  used 900  lbs.=  50  cu.  ft. 

Acetylene  used: 

50  cubic  feet @  $0.025     $1.25 

Oxygen  used: 

50  cubic  feet @     .02        1.00 

PREHEATING  COST 

Charcoal    

Gas,  \  hour,  2  burners @      .60          .30 

Kerosene 

LABOR  (Preparing)  : 

1  hour  30  min @     '.60          .90 

LABOR  (Welding)  : 

1  hour  30  min @      .60          .90 

LABOR   (Finishing  and  testing)  : 

1  hour        min @      .30          .30 

RODS: 

Lbs.  Steel @ 

15  Lbs.  Cast  Iron @      .10        1.50 

Lbs.  Bronze @ 

Lbs.  Copper @ 

Lbs.  Aluminum @ 

FLUX: 

\  Cans   Cast  Iron. . . . . . . . . . . . . .  „ . . . ......  @      .50          .25 


Total  $6.40 
REMARKS    . 


FIG.  255. — Suggestion  for  Cost  Card. 

A  decarbonizing  outfit  is  shown  in  Fig.  256.  Here  A  is  the 
oxygen  tank  valve,  B  the  tank  coupling,  C  the  pressure  gage 
showing  the  pressure  at  which  the  oxygen  is  delivered  to  the 


304 


GAS  TORCH  AND  THERMIT  WELDING 


"torch,"  D  the  regulating  screw,  E  hose  connection,  F  trigger 
valve,  G  hose  connection  and  H  the  flexible  copper  tip. 

To  use  this  outfit,  connect  it  up  as  shown,  then  with  the 
motor  running  shut  off  the  gasoline  and  let  the  motor  run 
down.  If  the  engine  is  particularly  dirty,  it  may  be  advisable 
to  protect  the  carburetor  and  pan  by  placing  some  asbestos 
paper  at  points  to  prevent  fires  from  flying  sparks. 


FIG.  256. — Imperial  Decarbonizing  Outfit. 

Remove  spark  plugs  from  cylinders — not  the  valve  caps. 
Crank  the  motor  until  the  cylinder  to  be  started  upon  has  the 
piston  at  the  top,  with  both  valves  closed. 

Set  the  pressure  on  the  regulator  at  about  fifteen  pounds 
and  partially  depress  the  lever  on  the  handle  of  the  carbon 
burner. 

Use  a  wax  taper  or  drop  a  lighted  match  into  the  spark 
plug  opening  of  cylinder,  at  the  same  time  directing  the  copper 


WELDING  SHOP  LAYOUT  305 

tube  of  the  carbon  burner  at  that  point.  This  ignites  the 
carbon,  and  if  it  is  not  too  dry,  the  oxygen  should  thereafter 
be  sufficient  to  completely  consume  it  without  again  lighting 
it.  At  the  start,  particularly  if  the  cylinder  is  oily,  there  will 
be  some  flame  as  well  as  considerable  sparks.  Hold  the  pressure 
down  until  the  flame  has  practically  disappeared,  then  press 
down  the  lever  all  the  way  and  move  the  nozzle  back  and  forth 
around  the  walls  until  sparks  stop. 

Sometimes  the  cylinder  is  very  dry  and  the  carbon  is  rather 
difficult  to  burn.  This  can  be  more  or  less  determined  by  the 
appearance  of  the  spark  plug.  If  it  is  dry,  squirt  about  a 
teaspoonful  of  kerosene  into  the  cylinder,  spreading  it  over 
as  large  a  surface  as  possible,  to  aid  the  burning. 

The  copper  tube  is  flexible  and  may  be  bent  as  desired 
to  reach  any  portion  of  the  cylinder.  Actual  contact  with 
the  carbon  by  the  tube  is  not  necessary  to  consume  it — carbon 
burns  in  an  atmosphere  of  oxygen  after  it  is  ignited. 

The  only  possible  danger  to  the  cylinder,  valves  or  piston 
is  a  too  high  pressure  of  oxygen  on  an  extremely  oily  cylinder 
— there  would  be  considerable  heat  generated  in  this  instance. 
Hold  the  pressure  down,  then,  until  the  flames  have  gone  and 
sparks  only  are  being  thrown  out  before  fully  opening  the  lever 
on  the  handle. 

When  through  cleaning,  it  is  desirable  to  remove  the  valve 
cap  and  blow  out  any  solid  particles  there  may  be  present; 
these  solid  particles  cannot  be  carbon,  but  may  be  pieces  of 
iron,  etc.  The  appearance  of-  the  cylinder  will  be  considerably 
improved  by  swabbing  off  the  top  of  the  piston  and  valves  with 
an  oily  rag. 

Carbon  burning  is  a  very  practical  solution  of  carbon  de- 
posits— but  care  and  horse  sense  must  be  used,  though  the 
process  calls  for  no  particular  degree  of  skill. 

SAFETY  RULES  FOR  GAS-TORCH  WORKERS 

The  following  rules  were  adopted  in  1920  by  the  Western 
Pennsylvania  Division  of  the  National  Safety  Council: 

EQUIPMENT  RULES 

1.  All  pressure  tanks  should  be  fitted  with  safety  relief  devices, 
and  tanks  not  so  equipped  should  not  be  used. 


306  GAS  TORCH  AND  THERMIT  WELDING 

2.  The  equipment  siiould  include  a  high-pressure  gage  to  indicate 
the  pressure  on  the  tank,  a  reducing  valve,  and  a  low-pressure  gage 
to  indicate  the  pressure  on  the  torch.     These  should  he  assemhled  as 
one  unit  and  so  arranged  that  they  need  not  be  separated  when  they  are 
attached  to,  or  detached  from,  the  tank.     The  two  gages  should  have 
different-sized  openings;  one  should  have  a  right-hand  thread  and  the 
other  a  left-hand  thread  so  that  they  cannot  be  interchanged.     There 
should  be  one  of  these  units  for  the  oxygen  tank  and  one  for  the 
acetylene  tank. 

3.  All  pressure  regulators  should  be  equipped  with  a  safety  relief 
valve  which  will  relieve  the  pressure  from  the  diaphragm   and  low- 
pressure  gage  in  case  the  high-pressure  valve  should  develop  a  leak. 

4.  Wire-wrapped  hose  should  not  be  used. 

5.  The  oxygen   and  acetylene  hose  should  be  of  different  color  or 
the  couplings  should  be  stamped  for  identification  purposes,  so  as  to 
avoid  interchanging  the  hose. 

6.  The  torches  should  be  of  a  type  which  will  not  backfire. 

RULES  FOR  OPERATION 

1.  Under  no  condition  should  acetylene  be  used  where  the  pressure 
is  greater  than  15  Ib.  per  square  inch. 

2.  Special  care  should  be  given  to  the  storage  of  oxygen  and  acet- 
ylene tanks.  Acetylene  is  classed  as  an  explosive,  and  only  a  limited 
number  of  containers  should  be  stored  in  any  one  place.    Oxygen  tanks 
should  be  stored  in  a  separate  place  from  acetylene  tanks. 

3.  Oxygen   and   acetylene   tanks  should   not   be   allowed   to   remain 
near   stoves,    furnaces,    steam   heaters   or   other   sources  of  heat,    and 
should   not  be   exposed  unnecessarily  to  the   direct   rays   of  the   sun, 
as  an  increase  in  the  temperature  of  the  gas  will  cause  a  corresponding 
increase  in  the  pressure  within  the  tank.     Any  excess  of  heat  may 
also  soften  the  fusible  safety  disk  with  which  the  tank  is  provided, 
causing  it  to  blow  out  and  permitting  the  gas  to  escape. 

4.  Oxygen   tanks   should  never  be  handled   on   the   same   platform 
with  oil   or   grease   which   might   find   their  way   into   the   valves   on 
the  tanks. 

5.  Oxygen  and  acetylene  tanks  should  never  be  dropped  nor  handled 
roughly,  and  should  never  be  stood  on  end  unless  fastened  so  as  to 
prevent  them  from  falling  over. 

6.  Tanks    should    not    be    handled    by    crane,    either    magnetic    or 
mechanical. 

7.  All  empty  tanks  should  be  marked  plainly  with  the  word  "empty" 
and  returned  promptly  to  the  storeroom. 

8.  An  open  flame  should  never  be  used  for  the  purpose  of  discovering 
leaks  in  acetylene  tanks.     Leaks  can  generally  be  detected  by  the  odor 
of  the  acetylene  gas,  and  their  location  can  be  determined  by  applying 
soapy  water  to  the  surface  of  the  tank  and  watching  for  the  soapy 
bubbles  formed  by  the  escaping  gas. 

9.  No  repairs  to  oxygen  or  acetylene  tanks  or  equipment  should  be 


WELDING   SHOP  LAYOUT  307 

made  or  attempted.     All  defects  should  be  reported  promptly  to  the 
foreman,  and  hy  him  to  the  manufacturer. 

10.  Leaking   acetylene   tanks    should    not   be   used,    but   should   be 
placed  in  the  open  air  and  all  open  lights  be  kept  away  from  them.    All 
leaking  acetylene  tanks  should  be  reported  promptly  to  the  foreman  and 
immediately  returned  to  the  manufacturer. 

11.  All  open    flames   should   be  kept   away   from   any  place  where 
there  is  any  possibility  of  acetylene  escaping. 

12.  Care  should  be  taken  to  protect  the  discharge  valves  of  tanks 
from  being  bumped,  as  a  jar  may  damage  the  valve  and  cause  it  to 
leak. 

13.  Grease  in  contact  with  oxygen  under  pressure  may  cause  spon- 
taneous ignition.     Great  care  should  be  taken   not  to  handle  threads 
or  valves  with  oily  hands  or  gloves,  and  gages  should  not  be  tested 
with  oil  or  any  other  hazardous  carbon.     If  a  lubricant  must  be  used, 
the  purest  glycerine  is  permissible. 

14.  Gages,  apparatus  and  torches  requiring  repairs  should  be  sent 
to  the  manufacturer,  and  local  repairs  should  not  be  attempted.    Valve 
seats  should  never  be  replaced  except  by  the  manufacturer. 

15.  The  use  and  operation  of  the  pressure   regulator  or  reducing 
valve  on  oxygen  or  acetylene  tanks  should  be  as  follows:    (a)   Open 
the  discharge  valve  on  the  tank  slightly  for  a  moment  and  then  close 
it.     This  is  to  blow  out  of  the  valve  any   dust  or  dirt  that  might 
otherwise   enter  the   regulator.      (b)    By   means   of   the   stud   or   nut 
connection   on   the   regulator,    connect  the   regulator  to   the  discharge 
opening  of  the  tank,     (c)  Release  the  pressure-adjusting  screw  of  the 
regulator  to  its  limit,     (d)   Open  the  needle  valve  slightly  if  there  is 
one.     (e)    Open  the  discharge  valve  on  the  tank  gradually  to  its  full 
width,     (f)   Open  the  needle  valve  to  its  maximum  if  there  is  one. 
(g)    Adjust  the  pressure-regulating  screw   until   the  desired  pressure 
is  shown  on  the  low-pressure  gage. 

16.  The   discharge   valves   on  the   tanks   should   be  opened   slowly, 
and   care  should   be  taken  to  avoid  straining  or  damaging  them   by 
the  use  of  a  hammer  or  the  wrong  kind  of  wrench.    A  special  wrench 
should  be  made  for  use  in  opening  these  valves  in  case  they  stick. 

17.  When  the  operation  of  the  cutting  or  welding  torch  is  stopped 
for  a  short  time,  the  needle  valve  on  the  regulator  should  be  closed, 
or  the  pressure-adjusting  screw  should  be  released  to  keep  the  pressure 
off  the  hose.     The  "torches  should  be  opened   momentarily  to  let  the 
pressure  out  of  the  hose  lines. 

18.  All  tanks  should  be  inspected  at  the  close  of  the  day's  work. 

19.  Proper  precautions  should  be  taken  to  protect  the  hose  from 
flying  sparks. 

20.  All  hose  should  be  examined  periodically  at  least  once  every 
week.     This  should  be   done  by  cutting  the  hose  off  at  the  end  of 
the   connection   and   examining  it.     In   addition,   after  a   few   months' 
use,  the  hose  should  be  cut  off  about  two  inches  back  of  the  connection 
and  examined  for  defects.    A  defective  hose  should  never  be  used. 


308  GAS  TORCH  AND  THERMIT  WELDING 

21.  Special  care  should  be  taken  to  avoid  the  interchange  of  oxygen 
and  acetylene  hose  or  piping,  as  this  might  result  in  a  mixture  of  these 
gases  that  would  be  highly  explosive.     The  practice  of  using  right- 
and  left-hand  threads  is  recommended. 

22.  White  lead,   grease,   or  other  similar   substances   should   never 
be  used  for  making  tight  joints.     All  joints  and  leaks  in  equipment 
should  be  made  tight  by  soldering  or  brazing. 

23.  The  oxygen  and  acetylene  valves  at  the  base  of  the  torch  should 
be  tested  daily  for  leaks. 

,  24.  Where  hydrogen  or  other  gas  is  used  instead  of  acetylene,  the 
same  precautions  should  be  observed  as  for  acetylene. 

25.  A  fire  extinguisher  should  be  carried  as  regular  equipment  to 
be  used  in  case  of  fire. 

26.  Men  using  welding  apparatus  should  wear  suitable  welding  gog- 
gles for  eye  protection,  having  frames  that  are  nonconductors  of  heat 
(not  celluloid),  side  shields  to  protect  against  hot  particles  of  metal, 
and  lenses  of  proper  color. 

27.  Operators'  clothing  should  be  fireproof. 

28.  If  valves  become  frozen,  they  should  be  thawed  by  hot  water, 
not  by  flame  or  hot  metal  rod. 

29.  Home-made  generators  should  never  be  used,  as  they  are  unsafe. 
Only  generators  permitted  by  the  Board  of  Underwriters  should  be 
used. 

30.  Where  acetylene  is  used  from  generators  or  is  piped  through 
the  plant,  an  approved  water  seal  should  be  interposed  between  the 
generator  and  the  piping  system,   and  individual  water  seals  should 
be  placed  at  each,  blow-pipe.     Water  seals  should  be  inspected  daily 
without  fail. 

31.  Portable  generators  should  not  be  used  inside  the  building. 

32.  Safety  devices  on  tanks,  generators,  or  apparatus  should  not  be 
removed  or  tampered  with. 

33.  In  welding  brass  or  bronze,  injurious  fumes  may  be  given  off, 
making  it  desirable  to  wear  a  respirator. 

34.  Smoking  while  on  duty  should  be  prohibited. 

35.  Electric  lights  in  a  generator  house  should  be  enclosed  in  vapor- 
tight  globes  protected  by  the  regular  guards. 

-36.  Snap  switches  should  be  placed  outside  of  the  generator  house 
in  a  suitable  place,  provided  the  house  is  isolated. 

37.  Piping  which  is  used  to  carry  acetylene  or  "hydrogen  should  be 
painted  a  distinctive  color. 

38.  The  manufacturers  should  provide  couplings  for  the  hose  which 
cannot  be  mistaken  and  put  on  the  wrong  hose.    If  the  couplings  could 
be  made  only  with  the  proper  connections,  it  would  be  impossible  to 
make  a  mistake. 

39.  In  storage  houses  where  hydrogen  or  acetylene  tanks  are  stored, 
the  wiring  should  conform  to  the  same  rules  as  for  the  generator  house, 
so  that  an  explosion  could  not  be   caused  by  defective   wiring  or  a 
break  in  the  bulb. 


WELDING  SHOP  LAYOUT  309 

40.  The  valves  on  the  piping  should  contain  neither  copper,  brass, 
nor  bronze. 

41.  In  opening  the  outlet  valve  of  a  full  tank,  do  not  remove  the 
regulator. 

42.  The   operator   should   not    stand   in   front   of   the   gages   when 
opening  the  discharge  valves  on  the  tank.     If  the  pressure  goes  off 
suddenly,  it  may  possibly  destroy  the  gage  and  the  glass,  and  parts 
will  be  blown  out  at  the  front. 

43.  A  label  should  be  placed  on  every  tank  of  oxygen,  stating  that 
it  should  be  kept  away  from  grease. 


RULES   FOR  WELDING 

The  following  rules,  adopted  by  the  Committee  on  Standards 
for  Locomotives  and  Cars,  U.  S.  Railway  Administration,  :for 
the  purpose  of  preventing  the  abuse  of  autogenous  welding 
for  purposes  for  which  it  is  not  well  adapted,  have  been  s,ent 
to  the  regional  directors  by  Frank  McManamy,  assistant 
director  of  the  Division  of  Operation,  with  instructions  to 
direct  all  roads  to  observe  the  rules  in  the  construction  or 
repair  of  locomotive  boilers,  so  that  any  failures  which  may 
have  been  caused  or  contributed  to  by  unrestricted  or  improper 
use  of  autogenous  welding  may  be  prevented. 

1.  Autogenous  welding  will  not  be  permitted  on  any  part 
of  a  locomotive  boiler  that  is  wholly  in  tension  under  working 
conditions,  this  to  include  arch  or  water  bar  tubes.  ?•  •„..,,..., 

2.  Staybolt  or  crown  stayheads  must  not  be  built  up  or 
welded  to  the  sheet. 

3.  Holes  larger  than  1|  in.  in  diameter  when  entirely  closed 
by  autogenous  welding  must  have  the  welding  properly  stayed. 

4.  In  new  construction  welded  seams  in  crown  sheets  will 
not  be  used  where  full  size  sheets  are  obtainable.     This  is  not 
intended  to  prevent  welding  the  crown  sheet  to  other  firebox 
sheets.    Side  sheet  seams  shall  not  be  less  than  12  in.  below  the 
highest  point  of  the  crown. 

5.  Only  operators  known  to  be  competent  will  be  assigned 
to  firebox  welding. 

6.  Where  autogenous  welding  is  done  the  parts  to  be  welded 
must  be  thoroughly  cleaned  and  kept  clean  during  the  progress 
of  the  work. 

7.  When  repairing  fireboxes  a  number  of  small  adjacent 


310 


GAS  TORCH  AND   THERMIT  WELDING 


patches  will  not  be  applied,  but  the  defective  part  of  the  sheet 
will  be  cut  out  and  repaired  with  one  patch. 


^ — > 


H«— ^ 


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s/ 

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s/ 

A0ovc  £TO£  ' 

V 

S2 

Afforc  £* 

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S3 

13 

W6 

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CZ 

Mm 

**t 

w 

>/?"£•  Mffi 

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FIG.  257. — Kinds  of  Welds  Tested  and  Examples  Used  as  Welding  Guides. 

8.  The  autogenous  welding  of  defective  main  air  reservoir 
is  not  permitted. 

9.  Welding  rods  must  conform  to  the  specifications  issued 
by  the  Inspection  and  Test  Section  of  the  United  States  Rail- 


WELDING   SHOP  LAYOUT 


311 


road  Administration  for  the  various  kinds  of  work  for  which 
they  are  prescribed. 


STRENGTH  OF  OXY-ACETYLENE  WELDS 

The  results  of  tests  made  by  the  Welding  Committee  of 
the  Emergency  Fleet  Corporation,  on  oxy-acetylene  welds  of 

TABLE  XVIII. — STRENGTH  OF  OXY-ACETYLENE  WELDS 


Mark 


Strength 

Kind  of      Ultimate        Per 
Weld         Strength     Sq.  In. 


Per     Av.  Per   Break 
Cent.       Cent.        In 


1                V  Sq. 
2 
3 

Butt 

tt 

50600 
50235 
49795 

50600 
50235 
49795 

92. 
91. 
90. 

91. 

Weld 

1-514        1"  Dia. 
1-515 
1-513 

tt 

43315 
44885 
45160 

55000 
56900 
57400 

100. 
100. 
100. 

100. 

«i 

1-511       2"  Dia. 
1-512 
1-510 

M 

15520 
149515 
153900 

47500 
46800 
48200 

86.5 

85.2 
87.5 

86.4 

tt 

2-516         iX1*" 
2-517 
2-518 

R.  Ang. 

7515 
7645 
7915 

40000 
40500 
42000 

73. 
73.5 
76.3 

74.2 

Bar 

2-519        iXU" 
2-520 
2-521 

M 

12605 
12820 
12150 

33600 
34000 
32300 

59.2 
61  .5 
59.0 

59.9 

Weld 

3-525         iX1*" 
3-526 
3-527 

Butt 

10890 
10775 
10935 

58000 
57500 
68500 

100. 
100 
100. 

100. 

Bar 
Weld 
Bar 

3-522         Jxli" 
3-523 
3-524 

u 

21460 
22025 
20785 

57000 
58600 
53300 

100. 
100. 
96.5 

98.8 

Bar 
Bar 
Weld 

4-528         ixU" 
4-529 
4-530 

Lap 

10970 
10725 
10965 

58500 
57500 
68600 

100. 
100. 
100. 

100. 

Bar 
Bar 
Bar 

4-531         IX1*" 
4-532 
4-533 

ti 

21905 

22085 
21435 

59300 
58700 
57000 

100. 
100. 
100. 

100. 

Bar 
Bar 
Bar 

5-537         iX1*" 
5-538 
5-539 

Tank 

2495 
2210 
2760 

13300 
11750 
12106 

24.6 
21.4 
22. 

22.6 

Bar 
Bar 
Weld 

5-534         iX1*" 
5-535 
5-536 

« 

4936 
5675 
5196 

13100 
15100 
15600 

23.8 
27.4 
24.7 

26.3 

Weld 
Bar 
Weld 

312  GAS  TORCH  AND  THERMIT  WELDING 

various  kinds  are  given  in  Table  XVIII.  The  1  and  2  in.  bars 
were  of  machine  steel,  turned  to  size  before  testing.  The  sheet 
was  steel  ship  plate.  The  careful  engineer  will  find  some  rather 
puzzling  discrepancies  in  this  table,  but  it  is  the  best  available 
at  the  present  time.  The  key  numbers  of  the  various  specimens 
will  be  found  to  correspond  to  the  types  of  welds  illustrated 
in  Fig.  257.  At  the  bottom  of  this  illustration  will  be  found 
examples  used  as  guides  for  welding  different  joints,  the  thick-. 
nesses  of  the  plates  and  end-spaces  being  indicated  in  the  table 
just  above  the  examples.  The  arrows  in  the  illustrations  of 
the  test  welds  indicate  the  direction  of  pull. 

-, '.'./' 

STRENGTH  OF  OXY-ACETYLENE  WELDED  PIPE 

The  Linde  Air  products  Co.,  Buffalo,  N.  Y.,  report  that 
they  made  some  tests  in  their  laboratory  in  1920,  to  determine 
the  strength  of  welded  pipe.  These  tests  were  intended  to  prove 
to  a  large  user  of  oil  pipe  from  Kansas,  that  properly  welded 
pipe  will  not  break  at  the  weld  under  pressure. 

According  to  the  report  made,  the  Linde  engineers  welded 
together  two  short  sections  of  standard  3-in.  iron  pipe,  threaded 
the  ends  and  screwed  on  two  standard  cast-iron  caps.  When 
the  cold  water  pressure  test  was  applied  to  the  breaking  point, 
the  top  of  one  of  the  caps  blew  out,  leaving  the  pipe  and  weld 
intact.  The  undamaged  cap  and  the  remaining  portion  of 
the  broken  cap  were  then  removed  and  two  extra  heavy  iron 
caps  were  screwed  on.  At  a  pressure  of  6,200  Ib.  per  sq.  in. 
one  of  these  caps  let  go,  still  without  injury  to  the  weld  or  the 
pipe.  Again  the  uninjured  cap  and  remnant  of  the  broken 
one  were  taken  off  and  extra  heavy  steel  caps  screwed  on. 
This  time  the  caps  held,  but  the  pipe  split  and  ripped  under 
the  added  pressure  upon  passing  the  elastic  limit,  tearing  up 
to,  and  being  effectually  stopped  by,  the  weld  which  refused 
to  give. 

The  next  test  was  made  with  4-in.  pipe.  Two  lengths  were 
welded  together,  the  ends  threaded  and  two  extra  heavy 
standard  caps  screwed  on.  In  this  test  .one  of  the  cap  heads 
blew  out  at  4,400  Ib.,  which  gave  a  total  end  pressure  on  the 
cap  of  approximately  33  tons,  proving  that  the  broken  cap  was 
not  in  any  respect  defective.  The  weld  was  not  impaired  at 


WELDING   SHOP  LAYOUT  313 

all.  After  this  test  it  was  suggested  that  an  entirely  new 
weld  with  other  pipe  lengths  of  the  same  diameter  be  tried. 
Accordingly  two  more  lengths  of  4-in.  pipe  were  welded, 
threaded  and  sealed,  this  time  with  extra  heavy  steel  caps 
made  to  withstand  a  working  pressure  of  3,000  Ib.  of  air.  The 
pressure  was  applied  and  the  pipe  gave  way  in  the  threads  at 
4,200  Ib.  In  all  of  the  tests  the  welds  held  securely. 


PART  II— THERMIT  WELDING 


CHAPTER  I 

THERMIT  WELDING:  ITS  HISTORY,  NATURE  AND 

USES 

The  affinity  of  finely  powdered  aluminum  for  oxygen, 
sulphur,  chlorine,  etc.,  is  such  that  it  is  utilized  to  effect  a 
reduction  of  metals  from  their  respective  oxides,  sulphides 
and  chlorides.  This  was  known  for  many  years  and  is  generally 
credited  to  Frederick  Wohler.  About  1894  Claude  Vautin 
found  that  when  aluminum  in  a  finely  divided  state  was  mixed 
with  such  compounds  and  ignited,  an  exceedingly  high  tem- 
perature was  developed  by  the  rapid  oxidation  of  the  aluminum. 
Since  fine  aluminum  will  not  burn  at  a  temperature  below  that 
of  molten  cast  iron  Vautin  and  others  first  heated  the  mixtures 
in  a  crucible.  The  result  was  that  the  initial  temperature  was 
so  high  at  the  moment  of  ignition  that  the  reaction  was 
explosive. 

Profiting  by  the  experiments  already  made,  Dr.  Hans  Gold- 
schmidt  of  Essen,  Germany,  discovered  a  method  of  igniting 
a  cold  mixture  of  fine  aluminum  and  iron  oxide  by  means  of 
a  barium-peroxide  fuse  which  was  set  off  by  means  of  a  storm 
match.  His  first  discovery  was  made  about  1895  or  1896  while 
trying  to  reduce  chromium  and  manganese.  Later  magnesium 
powder  or  ribbon  was  used  for  ignition  purposes,  being  set 
off  in  the  same  way.  A  mixture  of  a  few  pounds  of  the 
powders  was  found  to  burn  quickly  and  the  resulting  tempera- 
ture was  very  high.  The  original  patent  for  the  reduction  of 
metals,  upon  which  all  his  following  patents  were  founded, 
was  granted  March  16,  1897,  the  serial  number  being  615,700. 
Over  40  have  been  issued  since  and  more  are  pending.  About 
1898  Dr.  Goldschmidt  made,  used  of  his  reduction  method  to 
weld  two  pieces  of  iron  together.  From  this  time  on  the 
experiments  developed  and  difficulties  were  overcome  until  a 
process  was  evolved  for  the  commercial  use  of  the  reaction 

317 


318  GAS  TORCH  AND   THERMIT   WELDING 

for  welding  and  other  purposes.  The  process  so  developed 
was  called  the  Thermit  process.  The  company  handling  the 
mixtures  and  apparatus  was  originally  known  as  the  Gold- 
schmidt  Thermit  Co.,  but  in  1918  the  name  was  changed  to 
the  Metals  and  Thermit  Corporation,  New  York. 

The  present  Thermit  reaction  is  8Al+3Fe804=9Fe+4Al208. 
Expressed  in  weights  this  is  217  parts  aluminum  plus  732  parts 
magnetite =540  parts  steel  plus  409  parts  slag,  or  approximately 
3  parts  of  aluminum  plus  10  parts  of  magnetite  will  produce 
on  combustion  7  parts  of  steel.  The  steel  produced  by  the 
reaction  represents  about  one-half  of  the  original  Thermit  by 
weight  and  one-third  by  volume. 

Commercial  Thermit  is  a  mixture  of  finely  divided  aluminum 
and  less  finely  divided  magnetic  iron  scale.  The  aluminum  is 
about  like  granulated  sugar  and  the  scale  like  coarse  sand,  the 
ratio  by  weight  being  approximately  three  of  iron  scale  to 
one  of  aluminum. 

According  to  the  company  just  mentioned  the  average 
analysis  of  Thermit  steel  is : 

Carbon O.Of)  to  0.10 

Manganese   0.08  to  0.10 

Silicon    0.09  to  0.20 

Sulphur    0.03  to  0.04 

Phosphorus  0.04  to  0.05 

Aluminum   0.07  to  0.18 

Of  course  to  produce  a  steel  of  the  foregoing  composition 
the  aluminum  and  iron  scale  must  be  very  pure.  For  the 
mixture,  scale  from  Bessemer  or  open-hearth  steel  would  prob- 
ably come  close  to  meeting  commercial  demands.  The  average 
tensile  strength  of  a  Thermit  weld  of  the  foregoing  average 
composition  is  about  61,000  Ib.  per  square  inch.  This  can  be 
varied  by  adding  other  elements.  The  elastic  limit  is  slightly 
more  than  half  this  figure,  or  an  average  of  about  34,000 
pounds. 

Temperature  and  Characteristics. — While  the  temperature 
of  the  reaction  is  too  high  to  be  measured  by  a  pyrometer 
it  can  be  calculated  quite  accurately  theoretically  and  Prof. 
Joseph  W.  Richards  in  his  book  "Metallurgical  Calculations," 
gives  it  as  2694  deg.  C.7  which  is  equal  to  4881  deg.  F. 


THERMIT  WELDING:    ITS  HISTORY,  NATURE  AND  USES     319 

31.  Fery,  using  his  radiation  pyrometer,  found  the  temperature 
of  the  stream  of  steel  as  it  issued  from  the  crucible  to  be  2300 
deg.  C.  (4172  F.).  Making  allowance  for  the  chilling  effect 
of  the  crucible  this  is  probably  about  right.  Considering  the 
melting  point  of  steel  to  be  about  1350  deg.  C.,  Thermit  steel 
is  nearly  twice  as  hot. 

There  is  absolutely  nothing  explosive  about  the  present 
Thermit  reaction  and  no  danger  is  incurred  in  storing  it  or 
handling  the  material  owing  to  the  fact  that  it  takes  over 
1300  deg.  C.  of  heat  to  ignite  it.  It  is  for  this  reason  that  a 
special  ignition  powder  must  be  used  for  starting  the  reaction. 
The  ignition  powder,  however,  must  be  kept  away  from  heat, 
and  in  particular  the  box  containing  it  should  be  tightly  closed 
before  the  Thermit  reaction  takes  place,  so  as  to  prevent  any 
spark  from  dropping  into  it.  All  Thermit  materials  must  be 
kept  dry,  for  Thermit  that  has  once  become  wet  cannot  be 
restored  to  its  original  condition  by  drying. 

Plastic  and  Fusion  Methods. — There  are  two  different 
methods  of  using  Thermit  for  welding  purposes.  For  con- 
venience these  methods  may  be  designated  (1)  the  plastic 
method  and  (2)  the  fusion  method.  The  first  is  used  principally 
for  welding  together  the  ends  of  pipes.  Here  the  pipe  ends 
are  first  machined  off  so  that  they  will  fit  snugly  together. 
A  mold  is  then  placed  around  the  ends,  and  Thermit  is  poured 
into  the  mold  from  a  crucible.  The  Thermit  mixture  is  first 
placed  in  the  crucible  and  ignited  by  means  of  a  small  amount 
of  ignition  powder  set  off  by  a  match.  After  the  reaction  the 
molten  content  of  the  crucible  is  poured  into  the  mold  and 
around  the  pipe  ends.  By  pouring  from  the  top  of  the  crucible 
the  slag  enters  the  mold  first  and  surrounds  and  coats  the 
pipe  ends  and  the  inside  of  the  mold  and  thus  prevents  the 
pipe  ends  from  being  burned  through.  This  allows  the  Thermit 
to  heat  the  pipe  ends  to  a  welding  heat,  after  which  they  are 
forced  together,  causing  a  slightly  upset  welded  joint. 

The  second,  or  fusion  method,  is  the  more  commonly  used. 
In  using  this  method  a  mold  is  also  used  to  surround  the  parts 
to  be  welded,  but  the  parts  must  be  preheated — usually  to  a 
red  heat — in  order  to  prevent  the  Thermit  being  chilled  by 
contact  with  the  colder  metal  and  causing  an  imperfect  weld. 
The  Thermit  to  be  used  is  placed  in  a  cone-shaped  crucible 


320  GAS  TORCH  AND   THERMIT  WELDING 

so  made  that  the  melted  Thermit  steel  may  be  run  out  of  the 
bottom  into  the  mold,  thus  preventing  the  slag  from  getting 
into  the  mold  and  spoiling  the  perfect  fusion  of  the  parts. 
In  this  method  it  is  also  necessary  to  have  the  parts  to  be 
welded  some  distance  apart  in  order  to  give  the  Thermit  steel 
an  opportunity  to  properly  fuse  the  surfaces  desired  and 
produce  a  perfect  union.  The  distance  the  parts  are  separated 
depends  on  the  size  and  nature  of  the  pieces  and  whether  the 
weld  is  to  be  made  on  two  separate  pieces  or  is  merely  to  weld 
a  cracked  place. 

This  last  method  is  especially  adapted  for  welding  together 
large  heavy  parts  of  considerable  section,  on  account  of  the 
Thermit  steel  being  produced  and  introduced  into  the  weld 
quickly  in  bulk  and  thereby  resulting  in  but  one  contraction 
throughout  the  entire  mass  of  metal.  Provision  to  compensate 
for  this  contraction  can  always  be  made,  so  that  when  the 
metal  cools  there  will  exist  practically  no  strains.  Welds 
requiring  as  high  as  4000  lb.  or  more  of  Thermit  have  been 
completed  successfully.  A  big  advantage  of  the  process  is  that 
huge  welds  may  often  be  made  without  dismantling  the  machine 
or  structure,  thus  saving  an  enormous  amount  of  labor  and 
time  in  many  cases. 

Neither  method,  however,  is  commercially  or  practically 
adapted  to  welding  very  small  sections  or  long  seams  in  thin 
sections,  which  work  can  be  better  accomplished  by  the  oxy- 
acetylene  or  electric  welding  processes.  It  should,  however,  be 
used  for  welding  shafts  when  the  break  is  in  a  journal.  It  is 
interesting  to  note  in  this  connection  that  neither  the  oxy- 
acetylene  nor  the  electric  welding  processes  has  proved  practical 
for  welding  trolley  rails  together.  All  so-called  welded  joints 
by  those  methods  consist  merely  in  welding  plates  to  the  rails 
and  the  joint  therefore  is  never  really  eliminated.  The  Thermit 
process,  on  the  other  hand,  has  proved  extremely  efficient  and 
economical  for  this  work,  and  thousands  of  Thermit-welded 
rail  joints  have  been  in  service  for  years  in  all  parts  of  the 
world. 

Kinds  of  Thermit  Commonly  Used.— For  commercial  weld- 
ing purposes  there  are  now  produced  three  varieties  of  Thermit 
known  as : 

Plain  Thermit. 


THERMIT  WELDING:    ITS  HISTORY,  NATURE  AND  USES     321 

Railroad  Thermit. 

Cast-iron  Thermit. 

Plain  Thermit  is  simply  a  mixture  of  aluminum  and  iron 
oxide,  as  previously  stated,  and  is  used  in  making  pipe  welds 
and  welding  necks  on  mill  rolls  and  pinions  where  the  Thermit 
is  merely  used  as  a  heating  agent  to  bring  the  pipe  ends  up 
to  a  welding  temperature  and  the  roll  and  pinion  ends  to  a 
molten  state. 

Railroad  Thermit  is  plain  Thermit  with  the  addition  of 
£  per  cent,  nickel,  1  per  cent,  manganese  and  15  per  cent, 
mild-steel  punchings.  This  grade  is  used  in  connection  with  steel 
welds. 

Cast-iron  Thermit  is  plain  Thermit  with  the  addition  of  3 
per  cent,  ferrosilicon  and  20  per  cent,  mild-steel  punchings,  and 
is  used,  as  its  name  implies,  for  welding  cast-iron  parts. 


CHAPTER   II 
MAKING   PLASTIC    PROCESS   WELDS 

Taking  up  now  the  various  uses  of  the  three  varieties  of 
commercial  Thermit  we  will  first  describe  in  detail  the  hutt 
welding  of  pipe.  This  is  done  by  the  plastic  process  which 
is  especially  adapted  to  welding  joints  in  the  pipes  in 
refrigerating  plants  and  for  high-pressure  steam,  hydraulic  or 
compressed-air  pipe  lines.  It  is  also  applicable  to  the  welding 


FIG.  1. — Pipe-Facing  Machine  Open  to  Receive  Pipe. 

of  superheater  units  for  locomotives.  The  joints  so  welded 
are  permanent,  nonleakable  and  never  require  attention,  and 
the  original  cost  compares  very  favorably  with  that  of  the 
special  mechanical  joints  of  any  type  used  for  refrigerating 
or  high-pressure  purposes.  All  of  the  apparatus  necessary  for 
the  work  is  easily  portable,  so  that  the  work  may  be  done 
anywhere. 

In  preparing  pipe  for  butt  welding  it  is  first  necessary  to 
insure  that  the  ends  are  cut  square.  If  the  pipe  is  threaded 
the  threaded  portions  will  have  to  be  cut  off.  While  the 
ends  of  the  pipe  may  of  course  be  squared  by  various  mechanical 

322 


MAKING   PLASTIC  PROCESS  WELDS 


323 


324  GAS  TORCH  AND  THERMIT  WELDING 

means  the  company  handling  Thermit  makes  a  small  portable 
machine  for  the  purpose,  which  is  much  more  satisfactory 
to  use  than  anything  else.  This  device  is  shown  in  Fig.  1. 
The  operation  of  this  marliiiu'  is  so  obvious  to  any  mechanic 
that  further  explanation  of  its  operation  and  method  of  use 
would  be  needless,  except  to  say  that  the  crank  handle  by 
which  the  cutter  is  rotated  lias  a  ratchet  on  it  so  that  the 
cutter  may  be  worked  in  close  quarters. 

If  after  the  pipe  ends  have  been  faced  off  they  should 
become  tarnished  they  should  be  brightened  with  clean,  fine 
emery  cloth  or  a  flat  carborundum  stone,  but  in  no  case  should 
the  faced  ends  be  touched  with  a  file  or  the  fingers. 


— Pip*  HeM  in  Clamps.  Mold  Partly  Asmbfed. 

\Yhen  the  pipe  ends  have  been  properly  fared  off.  the 
pipe  is  lined  up  s*>  that  the  faced  ends  will  butt  squarely 
together  and  then  the  moid  is  put  in  piaee.  In  welding  coils 
or  bends  suit  a We  apparatus  should  be  rigged  up  to  keep  the 
pipe  ill  alignment*  \Vhere  the  pipes  are  ^kns*  together  in 
eoils  it  k  usually  possible  to  spring  out  the  p*pe  to  be  welded 
so  as  to  permit  the  adjustment  of  the  mold  and  **»•»!•» 

A  Pip^W«idin^  Outfit—  A  eoinplete  outfit  iW  wv4*fing  pip»\ 
tbe  faeinir  maehine,  is  sin^vn  in  ¥%  i    In  tkfe  ««*,  pieecs 
pipe  are  shown  at  ~4;  wvKtiivir  portio^^  of  TWradt  at  B; 

«it*Kt  at  0;  at  O  1$  tbe 
i;  F,  tun^b»ekK^  for  ^laivq^^  t»,  reiadlit 
tor 


MAKING  PLASTIC  PROCESS  WELDS  325 

of  clamps.  In  order  to  make  the  procedure  clearer  a  pipe-mold 
and  clamp  unit  is  shown  in  Fig.  3.  Here  the  pipe  is  shown 
securely  clamped  in  place  with  the  ends  butting  together. 
When  putting  this  apparatus  in  place  the  clamps  are  first 
adjusted  at  an  even  distance  from  the  ends  of  the  pipe  and 
securely  clamped.  The  two  tension  bolts  are  then  adjusted  so 
as  to  bring  an  even  bearing  all  around  on  the  pipe  ends,  but 
care  must  be  taken  not  to  put  such  a  tension  on  the  pipe 
that  it  will  buckle  when  heated.  Just  enough  tension  to  hold 
the  ends  securely  is  all  that  is  needed.  It  will  be  seen  that 
while  a  set  of  clamps  may  be  used  for  a  number  of  sizes  of 
pipe  a  mold  can  only  be  used  for  the  size  for  which  it  was 
made. 

How  the  Mold  is  Used. — The  lower  part  of  the  mold  is 


— Mold  Fully  Assembled  for  Weld. 

shown  in  place,  but  the  top  part  of  the  mold  is  shown  at  the 
left  ready  to  be  put  on.  The  slightly  beveled  recesses  in  the 
top  and  bottom  parts  of  the  mold  are  for  the  pouring  gate. 
Before  putting  the  top  part  of  the  mold  in  place  care  must 
be  taken  to  see  that  the  lower  part  is  blocked  up  or  held  so 
as  to  be  in  close  contact  with  the  pipe.  This  may  be  done 
by  means  of  wedges,  earth  or  any  other  means  at  hand  that 
will  stay  in  place  during  the  process.  With  the  top  part  of 
the  mold  in  place,  as  shown  in  Fig.  4,  the  operator  next  pre- 
pares the  Thermit  for  pouring.  This  is  done  by  placing  the 
crucible  tongs  on  the  ground  convenient  to  the  mold  and  then 
setting  the  crucible  in  the  jaws  of  the  tongs.  It  is  very  im- 


326  GAS  TORCH  AND  THERMIT  WELDING 

portant  that  the  crucible  be  thoroughly  dried  before  using, 
and  if  it  is  a  new  crucible  it  is  advisable  to  burn  a  pound  or 
so  of  Thermit  in  it  and  then  pour  the  contents  out  on  dry  sand. 
This  is  the  quickest  and  most  convenient  way  of  drying  a 
crucible.  The  operator  should  have  the  handles  of  the  tongs 
placed  toward  him  convenient  for  pouring  the  metal  when 
the  reaction  is  completed.  If  double  tongs  are  used,  as  some- 
times is  necessary  with  large  crucibles,  the  helper  should  stand 
opposite  the  operator  in  readiness  to  help  pick  up  the  crucible 
at  the  proper  time.  Blue  or  special  glasses  should  be  worn 
to  protect  the  eyes  from  the  glare  of  the  reaction. 

As  each  size  of  pipe  must  have  its  own  size  of  mold  so 
must  the  portions  of  Thermit  be  measured  out  in  order  to 
have  the  proper  amount  for  a  given  size  of  pipe.  This  is  taken 
care  of  by  the  concern  making  the  Thermit,  which  puts  it 
into  bags,  each  containing  a  certain  amount  of  Thermit  suit- 
able for  a  given  welding  job.  For  all  ordinary  jobs  this 
scheme  makes  it  unnecessary  for  the  operator  to  do  any  special 
calculating  in  order  to  know  how  much  to  use  in  order  to  do 
the  work  and  not  waste  material. 

Placing  and  Igniting  the  Thermit. — With  a  bag  containing 
the  proper  amount  of  Thermit  the  operator  pours  about  one- 
half  into  the  crucible  and  the  rest  in  a  hand  scoop  for  feeding 
into  the  crucible  during  the  reaction.  Having  therefore  one 
part  of  this  portion  in  the  crucible  and  the  remainder  in  a 
scoop  he  places  a  half  spoonful  of  ignition  powder  (barium 
peroxicTe)  in  one  spot  on  top  of  the  Thermit  in  the  crucible. 
This  is  set  off  by  means  of  a  parlor  match,  which  is  applied 
immediately  after  striking  and  before  the  head  is  burned  off, 
to  the  ignition  powder  itself  or  else  to  another  match  head 
set  into  the  ignition  powder. 

The  ignition  of  the  powder  in  turn  starts  the  Thermit 
reaction.  After  the  reaction  is  well  started  the  operator  adds 
the  rest  of  the  Thermit  from  the  scoop,  trying  to  keep  about 
one-half  of  the  surface  of  the  molten  material  covered  with 
unburned  Thermit,  and  pouring  in  a  steady  stream  until  all 
the  Thermit  is  in  the  crucible.  He  should  then  immediately 
grasp  the  crucible  with  the  tongs,  obtaining  a  firm  grip,  and 
pour  the  contents  into  the  mold,  the  slag  entering  first.  The 
pour  should  be  made  as  soon  as  the  Thermit  has  reacted  and 


MAKING   PLASTIC   PROCESS   WELDS  327 

the  slag  has  come  to  the  top.  The  crucible  and  tongs  are  then 
set  aside  and  a  short  time  is  allowed  to  elapse  for  the  Thermit 
mass  to  bring  the  ends  of  the  pipe  to  a  welding  heat.  Shortly 
after  pouring  the  operator  should  turn  the  tension  nuts  enough 
to  keep  a  constant  pressure  to  determine  when  the  pipe  begins 
to  soften.  He  should  then  wait  for  10  to  20  sec.,  depending 
on  the  weight  of  pipe,  and  then  force  the  ends  together  by 
means  of  four  quarter  turns  (one  complete  revolution)  of  the 
nuts.  It  usually  takes  about  10  sec.  from  the  time  the  pipe 
softens  for  it  to  reach  a  welding  heat,  or  from  45  sec.  to  1J 
min.  from  the  time  of  pouring. 

Removing  the  Mold. — After  the  clamps  have  been  drawn 
up,  the  mold  should  be  allowed  to  remain  in  place  for  3  or  4 
min.  longer,  after  which  the  clamps  can  be  removed  and  the 
cast-iron  mold  knocked  away  from  the  pipe  by  means  of  a 
hammer.  The  Thermit  steel  and  slag  will  come  away  from 
the  pipe  with  the  mold  and  can  be  knocked  out  of  the  mold 
afterward. 

Care  must  be  taken  in  every  case  that  a  complete  welding 
portion  be  used,  as  only  the  full  measure  of  Thermit  will 
give  a  good  weld. 

It  is  advisable  where  joints  are  being  welded  in  quantities 
to  have  several  molds  so  as  not  to  use  molds  continuously 
while  hot.  It  is  also  advantageous  to  allow  the  mold  with 
its  contents  of  steel  and  slag  to  remain  on  the  pipe  for  a 
considerable  time  before  removing.  If  they  can  be  left  10  to 
15  min.  it  is  all  the  better. 

It  has  been  found  in  practice  that  two  men,  one  facing  the 
pipe  with  the  pipe-facing  machine  and  the  other  doing  the 
welding,  can  complete  a  weld  inside  of  10  min.  and  that  it 
is  a  simple  matter  for  them  to  make  from  40  to  50  finished  pipe 
welds  a  day. 

It  must  be  understood  from  the  foregoing  that  the  slag 
that  forms  on  top  of  the  molten  material  in  the  crucible  is 
poured  into  the  mold  first.  As  soon  as  this  slag  strikes  the 
cold  pipe  and  inner  surface  of  the  mold  it  forms  a  protective- 
coating  which  prevents  the  superheated  liquid  steel  which 
flows  in  after  it  from  coming  in  direct  contact  with  either 
the  pipe  or  the  mold.  The  heat  of  the  entire  mass,  however, 
serves  to  bring  the  pipe  ends  to  the  desired  temperature.  The 


328 


GAS  TORCH  AND  THERMIT  WELDING 


method  of  pouring  will  be  understood  from  Fig.  5.  In  this 
cut  A  shows  the  slag  flowing  into  the  mold  and  coating  the 
pipe  and  inside  of  the  mold;  B  shows  the  slag  in  the  mold 
and  the  steel  following,  displacing  the  slag  in  the  bottom  part 


c 

FIG.  5. — Pouring  Slag  and  Steel  into  the  Mold. 


- 


FIG.  6. — Mold  for  Welding  Vertical  Pipe. 

of  the  mold,  and  C  shows  the  mold  about  half  full  of  steel, 
but  a  film  of  slag  separating  it  from  the  pipe  and  mold. 

The    foregoing   instructions   apply  to   welding   pipe   in   a 
horizontal  position.     Vertical  pipe,  however,  can  be  welded  in 


MAKING  PLASTIC  PROCESS  WELDS  329 

essentially  the  same  manner,  but  a  special  mold  is  required. 
This  mold  is  constructed  in  such  a  way  as  to  divide  the 
Thermit-steel  collar  into  two  parts,  so  that  it  may  be  readily 
removed  from  the  pipe  on  the  completion  of  the  weld.  The 
mold  also  has  a  different  type  of  pouring  gate,  as  will  be  seen 
in  Fig.  6. 

The  same  method  used  for  welding  pipe  may  be  used  for 
welding  bars  or  rods  of  mild  steel  or  wrought  iron  of  various 
sizes  and  shapes,  but  this  method  is  not  applicable  to  welding 
cast  iron  or  high-carbon  steel.  For  the  latter  work  another 
method  must  be  used. 

Cost  and  Strength  of  Pipe  Welds. — It  may  be  of  interest 
to  compare  the  cost  of  a  Thermit-welded  joint  with  that  of 
mechanically  coupled  pipe,  and  for  this  the  reader  is  referred  to 
Table  I,  which  was  taken  from  *  *  Reactions, ' '  which  is  the  house 
organ  of  the  Metal  and  Thermit  Corporation.  While  accurate 
determination  of  the  cost  that  will  cover  general  practice  is 
always  difficult  there  is  no  doubt  about  the  superiority  from 
every  standpoint  of  the  Thermit-welded  joint  where  a  solid, 
leak-proof  and  especially  strong  coupling  is  wanted.  For 
ammonia-pipe  or  similar  installations  the  solid  joint  is  one  that 
every  real  engineer  will  recommend. 

As  to  the  comparative  strength  of  a  Thermit-welded  pipe 
joint  the  following  is  taken  from  a  report  made  by  Prof. 
Frederick  L.  Pryor  of  Stevens  Institute  July  10,  1914: 

"Two  classes  of  pipe,  standard  weight  and  extra  heavy,  were  tested, 
the  sizes  selected  for  each  type  being  1  in.  and  1£  in.  Six  samples 
each  of  1-in.  standard,  1-in.  extra  heavy,  l^-in.  standard  and  l|-in. 
extra  heavy  were  selected  for  test,  three  being  used  for  the  bursting 
test  and  three  for  the  tensile  test.  One  specimen  was  left  in  its 
original  form  and  two  specimens  were  cut  in  half  and  joined  together, 
one  with  a  Thermit  weld  and  one  with  standard-threaded  couplings. 
One  specimen  of  each  size  and  type  was  subjected  to  tensile  and 
bursting  tests.  Standard-weight  couplings  were  used  for  standard  pipe 
and  extra  heavy  couplings  for  extra  heavy  pipe,  and  the  welded  speci- 
mens were  put  together  by  your  process.  The  thickness  of  the  material 
at  the  weld  was  afterward  determined  and  found  to  be  about  0.02  in. 
more  than  the  thickness  of  the  pipe  for  the  1-in.  specimens,  and  about 
0.075  in.  more  than  the  thickness  of  the  pipe  for  the  l|-in.  specimens. 
A  number  of  pieces  of  pipe  were  measured  to  check  the  thickness  with 
the  accepted  standard  and  each  specimen  was  within  the  tolerance  factor. 

"The  tension  tests  were  made  in  the  usual  manner,   except  that 


330 


GAS  TORCH  AND  THERMIT  WELDING 


a  plug  was  inserted  in  each  end  of  the  pipe  in  order  to  assist  the 
gripping  action  in  the  machine. 


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"The  bursting  test  was  made  by  pumping  oil  into  the  pipe  under 
pressure,  the  actual  pressure  to  force  the  plug  into  the  cylinder  being 


MAKING   PLASTIC   PROCESS   WELDS 


331 


determined  by  the  dimensions  of  the  pressure  plug  and  the  weight 
on  the  scale  beam. 

"In  the  tension  tests  all  the  pipes  joined  by  couplings  ruptured 
in  the  root  of  the  thread  at  the  coupling,  and  the  welded  samples 
ruptured  away  from  the  weld  with  one  exception. 

"In  the  bursting  tests  all  samples,  including  those  put  together  by 
couplings  and  welds,  ruptured  in  the  seam  of  pipe.  The  location  of 
the  ruptures  for  both  the  tension  and  bursting  tests  are  noted  in 
Table  II." 

TABLE  II. — RESULTS  OF  TENSION  AND  BURSTING  TESTS  ON  SCREW-COUPLED 
AND  THERMIT-WELDED  PIPE  JOINTS. 


1"  standard 

1/4"  standard.  .  . 
1"  extra  heavy. . , 
1M"  extra  heavy, 


DIMENSIONS  IN  INCHES 


Outside 
Diameter 

1.315 
1.660 
1.315 
1.660 


Inside 
Diameter 

1.049 

1.380 

.951 

1.272 


Thickness 
.133 
.140 
.182 
.194 


Ulti- 

Yield       mate  Burst- 
Character     Point,     Tensile  Approximate  Location         ing        Approximate  Loca- 
of  Pipe     (Actual),  Strength,  of  Rupture                Pres-         tion  of  Rupture 
Lbs.     (Actual),  sure, 

Lbs.  Lbs.  Sq.  In. 
1"  Standard 

Straight...    18,000    27,900  Between  grips                      11,580  Center  of  pipe 

Coupling..    17,250    20,320  Root  of  thread  at  coupling   9,260  6"  from  coupling 

Welded....    16,500    26,130  2^"  from  weld                    10,560  4"  from  weld 

1"  Extra  Heavy 

Straight...    19,200    34,730  Between  grips                      13,510  2"  from  end  of  pipe 

Coupling 18,770  Root  of  thread  at  coupling  13,310  3"  from  end  of  pipe 

Welded. ...  23  ,JDOO    34,970  8"  from  weld                        14 , 220  2"  from  end  of  pipe 


W  Standard 

Straight...   22,300  37,670 

Coupling...  21,380  28,500 

Welded,...  20,930  36,020 


Between  grips  9 , 440  7"  from  end  of  pipe 

Root  of  thread  at  coupling   8,050  7"  from  end  of  pipe 
At  weld  8,460  1  \tf  from  end  of  pipe 


l%"  Extra  Heavy 

Straight ...   29 , 380  50,620     Between  grips  1 2 , 900  1 Y2"  from  end  of  pipe 

Coupling...  29,100  29,100     Rootof  thread  at  coupling  12,770  2"  from  end  of  pipe 

Welded. ...   27 , 800  50,980  "  6"  from  weld  1 1 , 490  1"  from  end  of  pipe 


Professor  Pry  or  also  at  about  the  same  time  made  some 
vibratory  tests.     The  pipe  selected  was   l^-in.    extra  heavy, 


332  GAS  TORCH  AND  THERMIT  WELDING 

and  each  test  piece  was  composed  of  6-ft.  lengths  joined  to- 
gether by  the  coupling  or  weld.  The  Thermit  welds  were  made 
in  the  presence  of  Professor  Pryor  by  a  representative  of  the 
Thermit  company  and  were  regular  standard  Thermit  joints. 
These  12-ft.  pieces  with  a  joint  in  the  center  were  subjected 
to  a  vibratory  motion,  the  pipe  depressed  and  raised  2  in.  below 
and  above  the  center  line.  The  test  pipe  was  filled  with  water 
under  22  Ib.  pressure  in  order  to  show  the  first  failure  of  the 
material.  Two  tests  were  made  of  the  pipe  joined  with  extra 
heavy  screwed  coupling  and  one  test  of  the  welded  joint  pipe. 
The  reason  only  one  test  was  made  on  the  Thermit-welded 
pipe  was  that  the  number  of  deflections  on  it  was  about  250 
times  the  deflections  made  on  the  screwed  coupling,  with  no 
sign  of  any  deleterious  effect.  Both  the  screwed-joint  specimens 
broke  just  outside  the  coupling  in  the  root  of  the  thread  under 
6160  and  3430  vibrations  respectively.  The  Thermit  specimen 
was  vibrated  1,566,340  times,  after  which  it  was  removed  from 
the  test  and  at  the  time  no  injury  was  apparent.  The  speed 
of  these  vibrations 'was  about  225  vibrations  per  minute. 


CHAPTER    III 
FUSION    WELDING    OF    HEAVY   SECTIONS 

The  method  of  welding  heavy  sections  and  castings,  or 
the  fusion  method,  differs  considerably  from  that  used  for 
welding  pipe  joints.  For  one  thing  the  parts  to  be  welded 
must  be  preheated  to  a  red  heat  and  also  another  type  of 


FIGS.  7  and  9. — Sectional  View  of  Thermit  Automatic  Crucible  and  Method 

of  Lining  It 

FIG.    7. — AA,    magnesia    stone;    BB,    magnesia    thimble;  C,    refractory    sand;    Z>, 

metd    disk;    77,    asbestos    washer;    F,    tapping    pin.       FIG.  9. — Method    of    lining    a 

crucible — AA,  magnesia  stone;  BB,  luting  of  fire  clay;  C,  cast  iron  crucible  cone; 
D,  layer  of  wrapping  paper  or  newspaper. 

crucible  is  needed.  The  type  of  crucible  used  is  shown  in 
Fig.  7.  This  is  a  conical-shaped,  sheet-metal  receptacle,  or 
shell,  with  an  opening  in  the  lower  pointed  end.  In  use  this 
is  suspended  or  supported  above  the  gate  of  the  mold  by  means 
of  a  tripod,  bracket  or  other  support.  The  metal  receptacle 

333 


334  GAS   TORCH  AND  THERMIT  WELDING 

is  lined  with  magnesia  tar,  a  hard-burnt  magnesia  stone  being 
set  in  as  shown  at  A.  This  has  a  tubular  opening  in  it  into 
which  a  small  magnesia  thimble  B  is  pressed.  This  thimble 
provides  a  channel  through  which  the  liquid  Thermit  steel  is 
poured  into  the  mold.  The  object  of  making  the  crucible  so 
that  it  may  be  tapped  from  the  bottom  is  to  prevent  the  slag 
from  entering  the  mold,  which  is  directly  opposite  to  the 
procedure  for  welding  pipe.  The  hole  in  the  bottom  of  the 
crucible  is  closed  previous  to  putting  in  the  Thermit  mixture 
by  means  of  the  tapping  pin  F,  the  asbestos  washer  E,  the 
metal  disk  D  and  the  refractory  sand  C.  This  sand  is  put  up 
in  small  bags  for  the  ^purpose  by  the  company  selling  the 
mixture.  When  everything  is  ready  the  Thermit  is  put  into 


FIG.  8. — Tapping  a  Crucible. 

the  crucible  and  ignited  exactly  as  described  for  pipe  welding. 
After  the  reaction  the  tapping  pin  is  pushed  up  as  shown  in 
Pig.  8  and  the  molten  steel  allowed  to  run  out  into  the  mold. 

The  crucible  and  the  thimble  through  which  the  metal  runs 
after  the  reaction  are  two  of  the  most  important  factors  in 
the  whole  process.  The  high  temperature,  together  with  the 
violent  ebullition  of  the  molten  metal  during  the  reaction, 
necessitates  a  lining  that  is  not  only  mechanically  strong  but 
of  a  very  high  refractory  substance.  It  has  been  found  that 
magnesia-lined  crucibles  are  the  only  ones  that  satisfy  these 
conditions. 

Life  of  Lining  Prolonged  by  Patching  With  Magnesia  Tar. 
— As  refractory  as  this  material  is,  however,  the  crucibles 
that  are  used  to  any  extent  must  be  relined.  Sometimes  the 
life  of  a  lining  may  be  prolonged  by  patching  with  magnesia 


FUSION   WELDING  OF  HEAVY  SECTIONS  335 

tar  where  needed  and  then  baking  it.  While  any  good  mechanic 
can  scheme  out  ways  to  line  a  crucible  in  an  emergency  and 
may  use  fire  clay  on  occasion  the  following  method  is  given  as 
the  best  way: 

The  magnesia-tar  lining  material  should  be  heated  until 
it  becomes  plastic.  A  few  handfuls  are  then  placed  in  the 
bottom  of  the  crucible  shell  and  a  magnesia  stone  imbedded 
in  this  material,  as  shown  in  Fig.  9,  and  centered  over  the 
hole.  More  magnesia  tar  is  then  rammed  around  the  stone 
to  hold  it  firmly  in  place.  The  cast-iron  crucible  cone  should 
then  be  placed  in  position  with  the  small  projection  set  into 
the  hole  in  the  magnesia  stone.  The  upper  part  is  next  centered 
in  the  shell  by  means  of  wedges  inserted  at  equal  distances 
along  the  circumference.  The  magnesia  tar  is  then  rammed 
into  the  space  between  the  cone  and  the  shell  a  little  at  a 
time  and  tamped  hard.  On  the  density  or  hardness  of  the 
lining  depends  the  life  of  the  crucible.  Special  iron  tamping 
tools  with  flat  ends  should  be  used.  The  rammer  should  be 
pounded  well  with  a  good-sized  hammer  when  ramming  in 
the  lining.  Better  still  is  a  pneumatic  bench  rammer. 

Do  not  put  in  the  material  too  rapidly,  and  let  it  be  remem- 
bered that  the  better  and  more  uniform  the  tamping  the  longer 
the  crucible  will  last. 

As  the  mass  nears  the  top  the  wooden  wedges  should  be 
removed  as  the  lining  already  in  place  will  hold  the  cone  in 
position. 

The  Crucible  Ready  for  Baking. — When  completely  filled 
and  tamped  a  mark  should  be  made  with  a  piece  of  chalk  on 
the  cone  and  the  point  opposite  to  it  on  the  lining,  so  that 
when  the  cone  is  withdrawn  it  may  be  replaced  exactly  as 
before.  Then  take  the  cone  out,  exercising  care  not  to  disturb 
the  lining,  place  a  layer  of  wrapping  paper  or  newspaper  over 
the  tar  lining,  then  replace  the  cone  carefully,  so  that  the 
marks  previously  made  come  opposite  to  each  other.  After 
this  put  on  the  crucible  ring  and  lute  carefully  around  the 
top  with  fire  clay  to  protect  the  upper  part  of  the  lining  from 
the  heat  in  baking.  It  is  also  well  to  place  damp  fire  clay 
around  the  bottom  of  the  crucible  and  inside  of  the  stone  for 
the  same  purpose. 

The  crucible  is  now  ready  for  baking,  and  for  this  purpose 


336  GAS  TORCH  AND  THERMIT  WELDING 

it  should  be  placed  in  a  suitable  oven.  The  heat  should 
gradually  be  raised  until  the  cast-iron  cone  becomes  red  hot 
and  should  be  held  at  that  temperature  until  all  the  fumes 
stop  coming  off  from  the  tar,  after  which  it  can  be  allowed 
to  cool  gradually  before  removing  from  the  oven.  If  the 
crucible  is  baked  too  long  the  lining  will  appear  crumbly  and 
the  life  of  the  crucible  will  be  very  much  shortened.  Baking 
for  too  short  a  time  will  leave  some  of  the  tar  in  the  lining 
and  cause  a  violent  Thermit  reaction.  When  cool  the  clay 
luting  may  be  removed,  the  cone  taken  out  and  the  crucible 
is  ready  for  use. 

Thimbles. — The  portion  that  has  to  withstand  the  most 
severe  strain  of  all  is  the  part  at  the  bottom  of  the  crucible, 
or  walls  of  the  hole  through  which  the  metal  is  tapped.  It 
has  to  stand  the  wash  and  pressure  of  the  weight  of  the  moving 
liquid  metal  and  slag  under  great  heat. 

The  magnesia  stone  which  is  centered  in  the  bottom  of  the 
crucible  and  around  which  the  material  for  lining  is  packed 
has  a  tapered  hole  in  the  center.  The  thimbles  are  of  the 
same  taper  as  the  hole  in  the  magnesia  stone  and  are  set  into 
the  latter.  When  the  thimble  is  used  up  (either  through 
enlargement  of  hole  or  by  splitting)  it  can  be  knocked  out 
and  replaced  with  a  new  one,  so  that  the  full  life  of  the 
crucible  may  be  utilized.  Thimbles  should  be  wrapped  with 
one  layer  of  uncreased  paper  before  being  placed  in  position. 

Since  various  amounts  of  Thermit  must  be  used  for  dif- 
ferent sized  welds  the  crucibles  used  must  vary  accordingly, 
although  it  is  possible  on  occasion  to  use  more  than  one  crucible 
at  a  time  for  a  given  melt.  This  is  not  advisable,  however, 
unless  necessary.  For  lining  these  various  sized  crucibles  the 
Thermit  company  makes  magnesia  stones  and  thimbles  in 
certain  sizes  designated  by  numbers.  The  metal  cones  as  well 
as  crucibles  of  a  given  capacity  are  also  numbered.  All  of 
the  ordinary  sizes,  as  well  as  the  amount  of  magnesia  tar 
needed,  are  shown  in  Table  III. 

The  Care  of  Crucibles.— WTe  have  described  in  detail  the 
construction  of  automatic  crucibles  to  be  used  in  connection 
with  Thermit  welding,  and  it  might  be  well  to  include  a  few 
words  on  the  proper  care  of  these  crucibles. 

They  should  be  very  carefully  handled,  as  the  lining  is 


FUSION   WELDING  OF  HEAVY  SECTIONS 


337 


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338 


GAS   TORCH  AND   THERMIT  WELDING 


apt  to  crack  or  fall  out  under  rough  treatment.  It  is  also 
always  important  that  they  be  stored  in  a  dry  place,  as  the 
lining,  being  porous,  will  absorb  moisture,  and  a  moist  lining 
will  cause  violent  Thermit  reaction. 

After  a  crucible  has  once  been  used,  it  is  not  necessary 
to  clean  it  of  the  slag  adhering  to  the  inside,  as  this  is  a  very 
refractory  material  itself  and  can  do  nothing  but  help  preserve 
the  crucible  if  left  on.  At  the  bottom,  however,  in  the  vicinity 
of  the  stone  and  thimble,  the  slag  has  to  be  removed  so  as  to 
clear  the  "opening  of  the  thimble  or  permit  of  an  old  thimble 
being  knocked  out  and  a  new  thimble  inserted. 

Applications  of  Fusion  Welding. — With  the  construction 
and  method  of  using  the  automatic  crucible  in  mind  we  will 


POMH6GATE 


BASIN  TO  HOW  SLAG.. 


VEHTHOLES 


PREHEATING  GATE 
O=  Facing  1$  Fire  Sand,  faFireClqy,  !/3  Ground  Fire  Brick 
0  =  Loam  orMixtureof*/s  sharp  Sandys  fire Clay 
§i  =  Iron  P/ua  or  Sand  Flour  Core 
^  =  frame  •  =  Yc/lov  Wax 

FIG.  10. — Typical  Thermit  Mold  for  Heavy  Sections. 

next  take  up  the  welding  of  heavy  or  solid  sections  in  detail. 
In  order  to  make  this  clear  a  typical  Thermit  mold  is  shown 
in  Fig.  10.  With  this  illustration  to  refer  to  the  following 
directions  will  be  readily  understood: 

We  will  suppose  that  the  parts  to  be  welded  are  those  of 
a  broken  frame.  It  is  best  to  put  tram  marks  on  the  two 
sections  far  enough  back  from  the  fracture  to  be  outside  the 
mold  box  when  it  is  in  place.  These  are  convenient  to  measure 
from  when  allowing  for  the  contraction  of  the  Thermit  steel 
as  it  cools.  Next  cut  along  the  lines  of  the  fracture  so  that 
an  opening  of  from  1  to  1J  in.  is  provided.  Tho  amount  of 
the  opening  depends  on  the  size  of  the  sections  to  be  welded, 
but  in  no  case  should  it  be  less  than  an  inch.  If  it  is  a  diagonal 


FUSION  WELDING  OF  HEAVY  SECTIONS  339 

fracture  it  is  usually  best  to  cut  it  so  as  to  make  as  near  a 
vertical  opening  as  possible. 

There  are  various  ways  of  cutting  away  the  metal  for  the 
opening,  such  as  sawing,  drilling  and  chiseling,  but  the  best 
way  is  to  use  an  acetylene  and  oxygen  cutting  torch.  In  any 
case  the  opening  should  be  clear  enough  to  allow  the  free  flow 
of  the  Thermit.  Now  clean  the  ends  of  the  sections  thoroughly 
for  at  least  'four  inches  from  the  opening,  so  as  to  expose  the 
good,  bright  metal.  Be  sure  to  remove  all  dirt  or  grease  as 
far  back  as.  the  mold  box  will  reach,  so  that  when  the  mold 
is  rammed  up  and  heat  applied  there  will  be  no  grease  to  burn 
out  and  leave  a  space  between  the  mold  and  part  to  be  welded. 

If  the  oxy-acetylene  torch  is  used  for  cutting  be  sure  to 
remove  all  oxide  or  scale  left  on  the  parts  by  the  operation. 
Next  make  allowance  for  contraction  by  setting  the  parts  away 
from  each  other  a  sufficient  amount  to  make  up  for  the  con- 
traction of  the  Thermit  steel  and  adjacent  parts  in  cooling. 
This  should  be  varied  from  -§  in.  to  J  in.,  depending  on  the 
size  of  the  weld.  In  many  cases  it  is  necessary  to  obtain  this 
increased  space  by  forcing  the  sections  apart  with  a  jack  or 
other  mechanical  means.  In  other  cases,  such  as  the  welding 
of  a  double-barred  locomotive  frame,  it  will  be  necessary  to 
heat  an  opposite  member  by  means  of  a  flaming  burner  attach- 
ment on  a  double-burner  preheater  or  by  using  a  basket  fire. 
It  is  sometimes  advisable  to  construct  a  small  fire-brick  or  sheet- 
iron  furnace  around  such  a  section  in  order  to  confine  the 
heat  or  protect  other  parts  from  the  flame.  This,  however,  is 
done  only  at  the  time  of  preheating. 

With  the  parts  lined  up  and  proper  allowance  made  for 
contraction  they  are  ready  for  the  wax  mold. 

Wax-Pattern  Molds. — The  wax-pattern  molds  are  made  of 
yellow  wax,  as  indicated  in  the  illustration  of  a  typical  mold. 
This  wax  is  placed  in  a  pan  and  warmed  until  it  becomes 
plastic  or  else  melted  entirely  and  then  allowed  to  cool  until 
plastic.  This  wax  is  then  shaped  around  the  parts  to  be  welded 
in  the  form  of  a  collar  as  shown.  The  opening  between  the 
ends  should  also  be  filled  with  wax,  and  it  is  necessary  to 
provide  a  vent  hole  through  the  wax  extending  from  the 
location  of  the  heating  gate  to  the  riser.  The  best  way  to 


340 


GAS  TORCH   AND  THERMIT  WELDING 


do  this  is  to  imbed  a  piece  of  good  stout  twine  in  the  wax, 
which  can  be  pulled  out  after  the  pattern  is  formed. 

The  mold  box,  details  of  which  arc  shown  in  Fig.  11,  should 
then  be  placed  in  position  and  securely  blocked  up  so  that 
all  weight  will  be  removed  from  the  sections  to  be  welded. 

We  are  now  ready  for  the  molding  material.  This  should 
consist  of  one  part  fire  clay,  one  part  ground  fire  brick  and 
one  part  fire  sand.  This  is  used  for  the  facing  of  the  mold 
or  the  part  that  comes  in  contact  with  the  Thermit  steel.  If 


MATERIAL  LIST 
?  Sheets  46'  ?f*  •%>"  Iron  I  Shee+  S3  "•  /?  *  V  / 


P/ate'D  to  slide 

in  -for  backing  up 

Co  re  at  Hea  ti  na  Gate 


Bottom  o-F  Box"C"l  Req 


Front  End  Piece'A" 

For  Box  for  lZ"Mold 


Front  End  Piece  "A"     /e*^] 
For  Box  for  !5"Mo!d     <LI2/( 
1  Req                ^  /^ 

U 
i 

Bock  End  Piece's" 
For  Box  for  15"  Mold 
IReq 

*.^  ^  ' 

Back  End  Piece"B" 
For  Bar-far  l?"Mold 

,         ~^^ 

FIG.  11. — Design  and  Materials  Required  for  Standard  Mold  Box. 

it  cannot  be  obtained  in  the  vicinity  it  can  be  ordered  from 
the  Thermit  company.  This  material  should  be  well  riddled, 
mixed  dry  and  then  moistened  with  just  enough  water  so  that 
it  will  pack  well. 

Ramming  the  Mold. — In  ramming  up  the  mold  place  a  small 
amount  of  molding  material  in  the  box  and  ram  with  a  small 
rammer  around  the  edges  and  working  toward  the  center, 
keeping  the  mold  level,  and  ram  hard.  Too  much  emphasis 
cannot  be  laid  on  this  point,  for  in  the  construction  of  the 
mold  depends  the  safety  of  the  entire  welding  operation.  See 


FUSION   WELDING  OF  HEAVY  SECTIONS 


341 


to  it  that  the  material  is  well  rammed  underneath  the  pattern. 
There  should  be  a  wall  of  molding  material  at  least  4  in.  thick 
between  the  wax  pattern  and  the  mold  box  at  all  points,  as 
the  Thermit  steel  is  intensely  hot  and  ample  material  must 
be  provided  to  hold  it.  A  wooden  gate  pattern  for  the  pre- 
heating opening  should  be  set  at  the  lowest  point  of  the  wax 
pattern  and  leading  out  to  the  front  of  the  mold  box,  where 
an  opening  is  provided  for  it.  Where  the  sections  to  be  welded 
together  are  of  the  same  size  this  preheating  gate  should  be 
set  directly  in  the  middle  of  the  lowest  part  of  the  wax  pattern 
so  as  to  heat  both  sides  of  the  frame  equally.  Sometimes, 


PATTERN  FOR  POURING  GATE 
~T     K 


PATTERN  FOR  HEATING  GATE 


PATTERN  FOR  RISER 

FIG.  12. — Wooden  Patterns  for  Pouring  Gate,  Riser  and  Heating  Gate  of 
Mold.  These  Are  Large  Enough  for  Welds  Up  to  5  X  7  ln-  Larger 
Welds  Require  Proportionately  Larger  Patterns. 

however,  it  is  necessary  to  weld  a  light  frame  section  to  a 
heavier  one,  in  which  case  the  preheating  opening  should  favor 
the  heavier  section,  which  will  require  a  longer  time  to  heat 
than  the  light  section. 

With  the  preheating  gate  provided  for,  set  another  wooden 
gate  pattern  directly  above  it  and  one  inch  away  from  the 
wax  pattern  and  have  it  properly  shaped  for  the  pouring  gate. 
Drawings  for  these  various  patterns  are  shown  in  Fig.  12. 

Be  sure  that  the  molding  material  is  well  rammed  around 
these  patterns  so  that  it  will  not  "cut  out"  under  the  blast  of 
the  preheatcr. 


342 


GAS  TORCH   AND  THERMIT  WELDING 


At  the  highest  point  of  the  wax  pattern  place  the  riser 
pattern.  If  there  is  more  than  one  high  point,  place  a  riser 
pattern  over  each,  as  the  function  of  a  riser  is  to  hold  a  supply 
of  steel  which  will  remain  liquid  for  a  considerable  period  of 
time,  and  take  care  of  all  shrinkage,  so  that  when  a  "pipe" 
is  formed,  due  to  shrinkage,  this  pipe  will  appear  in  the  riser 
and  not  in  the  weld.  Also  the  riser  acts  as  a  depository  for 
loose  sand  or  other  foreign  matter  that  may  be  washed  into 


VATER TUBES,  ,GRATEBMS 

o  o  o 


......  T 

........  f-9^  ..........  -------  H     Section 

Throu9hTrough 


FIG.  13.  —  Method  Employed  in  Making  Welds  in  Inaccessible  Places. 

it  by  the  Thermit  steel  in  passing  through  the  mold  and  pre- 
vents this  material  from  clogging  in  the  weld.  It  sometimes 
happens  that  welds  are  made  at  a  point  where  a  wooden 
riser  pattern  cannot  be  withdrawn  conveniently.  In  such  cases 
a  piece  of  jacket-iron  pipe  may  be  used  and  left  in  the  mold 
after  ramming  up.  The  Thermit  steel  will  flow  into  this  open- 
ing and  simply  melt  the  iron  pipe  and  amalgamate  with  it. 
After  the  mold  is  all  rammed  up,  hollow  out  on  top  so  as 


,  FUSION  WELDING  OF  HEAVY  SECTIONS  343 

to  form  a  basin  in  which  the  slag  may  collect  so  as  not  to 
overrun  the  mold  box.  Then  vent  the  mold  thoroughly  by 
making  holes  with  a  vent  rod  made  from  8  to  10  gage  steel 
wire,  so  that  all  gases  in  the  liquid  metal  will  have  a  chance 
to  escape,  as  shown  in  the  typical  mold.  This  is  important. 

Now  lightly  rap  the  gate,  riser  and  preheating  opening 
patterns  and  draw  them  out  carefully,  wiping  away  any  loose 
sand  that  might  tend  to  fall  into  the  holes.  A  molder's  slick, 
trowel  and  lifter  are  very  useful  in  this  connection.  Then  cover 
the  various  openings  so  that  nothing  will  fall  into  them  and 
adjust  the  crucible  in  position  with  the  bottom  about  3  in. 
above  and  directly  over  the  center  of  the  pouring  gate. 
Where  this  cannot  be  done,  construct  a  runner,  as  shown  in 
Fig.  13,  to  lead  the  steel  into  the  pouring  gate  of  the  mold. 

Preheating  the  Mold. — The  mold  is  now  ready  for  preheat- 
ing. Set  the  burner  of  the  preheater  so  as  to  point  into  the 
heating  gate  of  the  mold  and  about  1  in.  from  the  opening; 
then  apply  the  blast.  It  is  best  to  start  easily  at  first,  as  too 
much  of  a  blast  would  tend  to  "cut"  the  mold.  The  wax 
will  burn  out,  leaving  a  perfect  mold  the  shape  of  the  wax 
pattern.  Keep  the  heat  going  until  the  mold  is  thoroughly 
dried  out  and  the  parts  to  be  welded  arc  brought  up  to  a 
good,  red,  workable  heat  such  as  would  be  required  if  the 
frame  was  to  be  hammered. 

While  the  preheating  is  in  progress  the  charge  of  Thermit 
and  additions  should  be  placed  in  the  crucible,  which  is  first 
plugged  in  accordance  with  the  directions  previously  given. 
It  is  important  to  put  in  a  few  handfuls  of  Thermit  first  before 
dumping  in  the  rest  of  the  charge,  so  as  not  to  disturb  the 
plugging  material.  Mix  the  Thermit  charge  thoroughly  before 
putting  in  the  crucible.  No  ignition  powder  should  be  added 
until  the  Thermit  charge  is  ready  to  be  ignited.  If  the  Thermit 
charge  when  leveled  off  comes  closer  than  2  in.  to  the  top 
of  the  crucible  or  if  the  crucible  has  to  be  tipped  slightly  it  is 
best  to  build  up  the  crucible  by  means  of  a  ring.  This  ring 
should  be  less  in  diameter  than  top  of  crucible  so  it  can  set 
in  the  crucible  about  1  in.  It  should  be  from  8  to  10  in.  high 
and  made  from  J-in*  stock.  Lute  with  fire  clay  between  ring 
and  crucible. 

When  it  is  assured  that  the  frame  is  at  a  good  workable 


344  GAS  TORCH  AND  THERMIT  WELDING 

heat  quickly  remove  the  preheater  and  direct  it  down  the  riser 
so  as  to  blow  out  any  sand  or  dirt  that  may  be  in  the  mold. 
If  the  riser  is  difficult  of  access  direct  the  burner  down  the 
pouring  gate.  Then  plug  the  preheating  hole  with  a  piece 
of  fire  brick  ground  to  fit  or  an  iron  plug  inserted  as  shown 
in  Fig.  10.  Back  this  up  with  several  shovelfuls  of  molding 
material  between  the  mold  box  and  steel  plate  provided  for 
the  purpose  and  then  pack  the  sand  down  hard  with  a  rammer. 
This  will  prevent  any  possibility  of  the  Thermit  steel  running 
out  through  the  preheating  opening.  All  heating  apparatus 
should  be  removed  to  a  safe  distance  while  the  Thermit  reac- 
tion is  in  progress. 

IGNITING  THE  THERMIT 

Place  one-half  teaspoonful  of  ignition  powder  on  top  of 
the  Thermit  in  the  crucible  (Thermit  will  not  ignite  from  the 
heat  of  the  preheater  and  the  reaction  cannot  be  started  with- 
out ignition  powder).  Ignite  this  with  a  parlor  match,  apply- 
ing the  same  immediately  after  striking,  or  else  ignite  with 
a  red-hot  iron ;  this  often  fs  the  easier  method.  It  is  important 
that  ample  time  be  allowed  for  the  completion  of  the  reaction 
and  for  the  entire  fusion  of  the  punchings,  which  are  mixed 
with  the  Thermit.  It  is  best  to  wait  at  least  35  sec.  before 
tapping  the  crucible.  This  is  accomplished  by  knocking  up 
the  tapping  pin  which  sets  in  the  bottom  of  the  crucible,  using 
for  the  purpose  the  tapping  spade  or  a  flat  piece  of  iron  IjXi 
in.  by  4  ft. 

Hold  up  the  expansion  on  the  parts  with  a  jack  or  pre- 
heater until  the  metal  in  the  weld  has  set  and  shrinkage 
commences  to  set  in;  then  remove  the  jack  or  shut  off  the 
heat.  This  should  be  usually  done  about  two  or  three  hours 
after  the  weld  is  made,  but  depends  largely  on  the  size  of  the 
section  and  length  of  preheating. 

The  mold  should  be  allowed  to  remain  in  place  as  long  as 
possible,  preferably  over  night,  so  as  to  anneal  the  steel  in 
the  weld.  In  no  case  should  it  be  disturbed  for  at  least  six 
hours  after  pouring. 

After  removing  the  mold,  drill  through  the  metal  left  in 
the  riser  and  pouring  gate  and  knock  these  sections  off,  or  else 
cut  them  off  with  an  oxy-acetylene  torch. 


FUSION  WELDING  OF  HEAVY  SECTIONS 


345 


Amount  of  Thermit  Needed  for  Welds. — The  amount  of 
Thermit  needed  for  welding  sections  of  different  sizes  can  be 
derived  from  Table  IV,  which  contains  the  proper  proportions 
of  manganese,  nickel  and  punchings.  These  amounts  are  given 
on  the  supposition  that  the  Thermit  collar  or  reinforcement 
is  made  in  accordance  with  the  dimensions  published  in  the 
table. 

TABLE  IV.— WELDING  PORTIONS  FOR  WELDING  RECTANGULAR  SECTIONS. 


Width'  of 
Section 

Depth  of 
Section 

Width  of 
Thermit 
Steel  Collar 

Thickness  of 
Thermit  Steel 
Collar  at  Center 

Quantity  of   . 
Railroad  Thermit 
Required  for  Weld 

Inches 

Inches 

Inches 

Inches 

Pounds 

3 

2 

4 

40 

3 

2l/ 

4 

40 

3 

3  2 

4 

45 

3 

4 

50 

3 

4 

4 

55 

4 

4 

4 

65 

4 

4 

65 

4 

5 

4 

70 

4 

5 

% 

75 

4 

6 

5 

% 

75 

4H 

5 

M 

70 

4V 

5 

5 

/4 

75 

4'H 

5 

J4 

75 

4V£ 

6  2 

5 

Ji 

80 

5 

5 

5 

M 

75 

5 

5 

J4 

80 

5 

6  2 

6 

J^ 

85 

5 

7 

6 

i^ 

90 

6 

i/£ 

85 

5H 

g 

6 

H 

90 

7 

6 

i^ 

110 

6 

6 

6 

L^ 

100 

6 

6 

i^ 

120 

6 

7 

7 

5^ 

130 

7 

IN? 

130 

BJ/ 

7 

7 

1^ 

150 

?H 

8 
7 

7 
7 

18 

160 
155 

It  is  better  practice,  however,  to  calculate  the  amount  of 
Thermit  needed  for  a  weld  from  the  weight  of  wax  used  in 
the  pattern  and  it  is  advisable  anyway  to  make  this  calculation 
as  a  check. 

Where  the  quantity  of  Thermit  is  calculated  from  the  wax 
great  care  should  be  taken  to  see  that  the  entire  space  which 
is  to  be  filled  with  Thermit  steel  is  filled  with  wax  so  that 
not  only  the  collar  but  the  space  between  the  sections  is  filled 
with  wax.  Then,  by  weighing  the  wax  before  and  after  the 


346  GAS  TORCH   AND  THERMIT  WELDING 

completion  of  this  operation,  the  difference  will  be  the  quantity 
of  wax  used,  and  this  weight  in  pounds  multiplied  by  30  will 
give  the  proper  amount  of  railroad  Thermit  for  the  weld. 

It  is  recommended  that  railroad  Thermit  be  used  in  all 
cases,  as  it  is  ready  mixed  with  1  per  cent  pure  manganese, 
|  per  cent  nickel  shot  and  15  per  cent  mild-steel  punchings. 
This  has  been  found  to  give  the  best  results  for  welding 
wrought  iron  and  steel.  For  convenience  railroad  Thermit  is 
supplied  in  waterproof  paper  bags  holding  29J  Ib.  of  the  mix- 
ture, so  that  one  bag  to  the  pound  of  wax  is  sufficient  for  a 
weld.  This  rule  provides  ample  Thermit  steel  not  only  for 
the  weld  proper,  but  also  for  the  pouring  gate  and  riser. 

In  case  the- user  has  only  plain  Thermit  on  hand  he  should 
then  allow  25  Ib.  of  plain  Thermit  to  the  pound  of  wax,  and 
should  mix  with  this  amount  of  plain  Thermit  1  per  cent  pure 
manganese,  f  per  cent  nickel  shot  and  15  per  cent  mild-steel 
punchings.  In  other  words,  to  every  100  Ib.  of  plain  Thermit 
add  1  Ib.  pure  manganese,  10  oz.  nickel  shot  and  15  Ib.  mild- 
steel  punchings.  These  punchings  must  be  clean  and  free  from 
grease  or  dirt  of  any  kind  and  not  more  than  f  in.  in  diameter 
by  J  in.  thick. 

These  rules  apply  only  to  welds  requiring  less  than  300  Ib. 
of  Thermit.  For  welds  requiring  more  than  300  Ib.  of  Thermit 
the  usual  mixture  takes  20  per  cent  mild-steel  punchings  with 
the  other  additions  the  same.  If  railroad  Thermit  is  used  add 
3|  Ib.  of  punchings  to  each  bag.  In  special  cases  it  is  some- 
times advisable  to  make  up  a  special  mixture  in  order  to 
produce  a  Thermit  steel  of  essentially  the  same  analysis  as 
the  steel  in  the  parts  to.  be  welded.  Where  the  amount  of 
Thermit  calculated  comes  to  ten  bags  or  more,  one  of  these 
bags  may  be  dispensed  with ;  that  is,  instead  of  using  ten  bags 
use  nine,  or  instead  of  using  20  bags  use  18,  and  so  on,  as 
the  smaller  percentage  of  metal  required  for  gates  and  risers 
makes  it  unnecessary  to  use  so  much  of  the  mixed  Thermit. 

Where  it  is  desired  to  calculate  in  advance  the  amount 
of  Thermit  required  for  a  weld  it  is  first  necessary  to  estimate 
the  number  of  cubic  inches  in  the  space  to  be  filled  with  Thermit 
steel,  i.e.,  the  space  between  the  ends  of  the  sections  to  be 
welded  together  and  the  cubical  contents  of  the  Thermit-steel 
collar  or  reinforcement  fused  around  the  weld.  Allow  J  Ib. 


FUSION   WELDING  OF  HEAVY  SECTIONS 


347 


of  railroad  Thermit  to  the  cubic  inch,  and  this  will  be  sufficient 
not  only  for  the  weld  proper  but  will  provide  ample  metal 
for  pouring  gate  and  riser.  In  estimating  the  cubical  contents 
of  the  collar  the  simplest  method  is  to  multiply  the  width  by 
the  greatest  thickness  (i.e.,  the  thickness  at  the  middle  part) ; 
then  multiply  this  product  by  0.7.  This  will  give  the  average 
area  of  the  cross-section  of  the  collar.  If  this  is  then  multiplied 
by  the  total  length  of  the  collar  around  the  outside  of  the 
frame  and  if  all  measurements  are  taken  in  inches  the  result 
will  be  the  number  of  cubic  inches  in  the  collar. 


VZori< 


W>V'^:-:VV'vZ 6 n e  ;AV':-:-'Xfr' ##VV'-'#5? ^ZQng^Di:^   ^ZofiieviC-f 


<  Jack  for  D-> 


l!:''..vZo  nc 


ack  here  or  here  to  Line  up 

FIG.  14. — Method  of  Preventing  Unequal  Stresses  When  Welding  Locomo- 
tive Frames  Broken  at  Various  Points. 

Fracture  Location  Remarks 

Zone  A* Heat  zone  B  to  get  9-lc  in.  expansion  and  hold  2  to  3  hours 

after  welding.     Preheater  or  basket  fire.* 
Zone  B* Heat  zTTne  A  to  get  -Mo   in.  expansion  and  hold  2  to  3  hours 

after  welding.     Preheater  or  basket  fire.* 
Zone  C,  Cj  or  Cr .  .  .' Jack   3A&  in.  at  C,  Ct  or  C2;  keep  jack  in  place  2  to  3  hours 

after  welding  and  then  remove  entirely. 
Zone  D  or  D, Jack  3/is  in.  at  D  or  O,;  keep  jack  in  place  2  to  3  hours  after 

welding  and  then  remove  entirely. 
Zone  E Cut  out  unfractured  member  of  splice  to  clear  collar. 

*  When  heating  either  Zone  A  or  Zone  B  the  adjacent  pedestal  brace  or  braces 
should  be  put  in  place  before  commencing  to  heat  so  as  to  distribute  the  expansion 
and  not  upset  or  distort  the  leg. 

Locomotive  Frame  Work. — The  foregoing  directions  refer 
to  the  general  run  of  Drought-iron  or  steel  repairs,  but  with 
only  slight  variations  the  same  method  is  followed  for  locomo- 
tive-frame work.  The  principal  difference  is  in  placing  the 
mold  or  allowing  for  contraction  in  various  members  and  not 
in  the  use  of  the  Thermit  itself.  In  order  to  make  it  clear 
where  stresses  are  liable  to  be  set  up  in  a  locomotive  frame 
the  diagram  shown  in  Fig.  14  has  been  made.  P>y  a  careful 
study  of  this  and  the  application  of  the  principles  illustrated 
a  welder  should  be  able  to  figure  out  his  work  so  as  to  produce 
satisfactory  results. 


348 


GAS  TORCH  AND  THERMIT  WELDING 


The  illustrations  will  be  of  assistance  in  planning  the  work 
on  various  parts  of  a  locomotive  frame.  Fig.  15  shows  how 
to  place  the  mold  and  jacks  for  welding  a  broken  frame  leg. 
With  the  pouring  gate  and  risers  as  indicated  they  permit  of 


Section  Throuqh 
Thermit  Collar 


POURING  GATE 


HE  AT  ING  GATE 
Section  on  A-B 


V\Shaded  Portion 
\    yv  be  cut  away 

\andFrametvbe 
1   yacked apart  ty" 


FIG.  15. — Method  Employed  in  Welding  Locomotive  Frame  Broken  in  Leg. 


'0 


K 4  H 

Section  Through  ThermitCollnr 

This  Section  applies  to 
Frames  up  tr>  4*  5;  for 
Dimensions  of  Collars  on 
Larger  Frames  see  Table 


HEATING  GATE 
Section  on  A-B 


Frame  Ready  for  Mold 


JACK  HERE  OR  HERE  TO  LINE  UP 

FIG.  16. — Method  Employed  in  Welding  Locomotive  Frame  Broken  in  Jaw. 

a  good  washing  action  for  the  Thermit  steel,  so  that  any  slag 
or  sand  that  might  be  in  the  mold  will  be  carried  into  the 
risers. 

Fig.  16  shows  how  to  weld  a  frame  broken  in  the  jaw. 


FUSION   WELDING  OF  HEAVY  SECTIONS 


349 


Fig.  17  shows  how  to  weld  a  frame  broken  in  the  splice. 
In  this  it  is  best  in  making  the  repair  not  only  to  weld  the 
broken  sections  together,  but  also  to  cut  out  a  piece  about 
1X5  in.  of  the  unbroken  member,  so  the  Thermit  will  flow 
entirely  around  the  broken  sections.  By  making  the  repair 
in  this  manner  a  good,  strong  job  is  assured,  and  if  the  bolt 
hole  is  welded  up  and  the  two  members  welded  together  future 
breakage  at  these  particular  points  is  practically  eliminated. 


POURIHGGATE 


To  avoid  welding  fo  Tongue.coat 
this  Surface  with  Black  Lead 


FIG.  17. — Method  of  Welding  Frames  Broken   in   Splice.     Lower  Drawing 
Shows  How  to  Drill  and  Cut  the  Unbroken  Member. 


The  only  objection  that  can  be  raised  against  this  practice 
is  the  trouble  of  separating  the  members  in  case  the  splice  is 
to  be  removed  or  in  order  to  take  out  or  renew  a  cylinder. 
This  objection,  however,  is  not  serious  because  it  is  only  neces- 
sary to  drill  a  line  of  small  holes  where  the  parts  are  welded 
together  and  the  member  can  then  be  removed.  When  replac- 
ing it  is  best  to  cut  a  keyway  where  the  frame  is  cut  out  and 
then  bolt  together  in  the  same  way  as  when  the  frames  were 
originally  assembled. 


350 


GAS  TORCH  AND  THERMIT  WELDING 


Fig.  18  shows  how  to  weld  locomotive  mud  rings  without 
cutting  the  sheets.     This  method  has  proved  entirely  satisfac- 


•HCATINGGATE 
Section  Showing  Weld,Gates  and  Risers 


TO/AM  HOLES,/  DEEP 
DRILLED  INTO  MUDRING 

Side  Elevation 
Showing  Weld 


Section  Showing  Prepared 
Mold  in  a  Standard  Mold  Box  . 

FIG.  18.— Mold  for  Welding  Mud  Rings  Without  Cutting  Sheets. 


FIG.  19 Thermit  Weld  on  Mud  Ring. 

tory  and  many  such  welds  have  been  completed  and  are  giving 
good  service. 

Typical  Welds.— Fig.  19  is  that  of  a  finished  mud-ring  weld, 
in  which  the  sheets  are  -not  cut. 


FUSION   WELDING  OF  HEAVY  SECTIONS  351 


FIG.  20. — Fracture  in  Crosshead  Cut  Out  for  Welding. 


FIG.  21. —  Weld  Completed  and  Crosshead  in  Service. 


352  GAS  TORCH  AND  THERMIT  WELDING 

Fig.  20  shows  a  fracture  in  a  crosshead  cut  out  for  welding. 
Fig.  21  shows  the  weld  completed  and  the  part  in  service. 


FlG.  22. — Weld  on  Broken  Bocker  Shaft  Before  Machining 

Fig.  22  shows  a  weld  on  a  broken  locomotive  rocker  shaft 
before  machining. 


FIG.  23. — Repair  on  Broken  Guide  Yoke. 

Fig.  23  shows  a  repair  on  a  broken  guide  yoke. 
Fig.  24  illustrates  two  welds  in  an  engine  splice. 


FUSION   WELDING   OF  HEAVY  SECTIONS  353 

Fig.  25  is  a  repaired  driving-wheel  center. 

Fig.  26  shows  details  of  a  crucible  holder  for  frame  welds. 

No  attempt  has  been  made  to  make  the  list  of  repairs  on 
locomotive  parts  complete,  but  enough  has  been  shown  to  serve 
as  a  guide  for  practically  everything  that  is  apt  to  confront 


FIG.  24. — Two  Welds  in  Splice  of  "Frame. 

the  practical  man.  For  superheater  work,  or  pipe  work  of 
any  kind,  the  directions  given  under  the  heading  of  pipe  weld- 
ing will  cover  all  that  is  necessary. 

As  a  sort  of  recapitulation  of  the  foregoing  directions,  it 
will  be  well  to  keep  the  following  "don'ts"  in  mind  when 
getting  ready  for  all  locomotive  Thermit-welding  work. 


354  GAS  TORCH   AND  THERMIT  WELDING 

Don't  keep  your  material  and  appliances  in  a  damp  place. 
Better  store  them  all  in  a  good,  dry  room  under  lock  and  key, 
the  foreman  in  charge  of  the  Thermit  work  to  have  the  key. 
Better  still  construct  a  tool  wagon  and  keep  all  Thermit 
material  in  it. 

Don't  start  to  make  a  Thermit  weld  unless  you  have  all 
the  necessary  materials  and  appliances  and  the  latter  in  good 
condition. 

Don't  neglect  to  clean  the  frame  thoroughly.     Be  sure  to 


FIG.  25. — Weld  on  Driving- Wheel  Center. 

remove  all  the  grease,  paint,  etc.,  and  have  as  good  clean  metal 
as  possible  to  work  on. 

Don't  neglect  to  take  care  of  the  contraction  that  is  bound 
to  be  set  up  as  the  metal  in  the  weld  cools.  If  this  cannot 
be  allowed  for  by  spreading  the  sections  with  a  jack  or  other 
mechanical  means  heat  the  opposite  unbroken  member  with 
the  other  burner  of  a  double-burner  preheater  fitted  with  a 
flaming-burner  attachment.  If  this  is  not  available  hang  a 


FUSION  WELDING  OF  HEAVY  SECTIONS 


355 


basket  fire  of  charcoal  or  coke  about  the  unbroken  member 
and  heat  until  proper  expansion  is  obtained,  holding  up  the 
heat  for  two  or  three  hours  after  the  weld  is  poured.  It  is 
advisable  to  expand  the  frame  3/16  in.  on  the  average.  Cut 
out  the  frame  along  the  fracture  so  as  to  make  a  clean  opening 
1  in.  wide.  Proportion  your  wax  pattern  to  the  size  of  the 
frames  as  shown  in  the  table. 


STEEL 


•  •-•&-£>  —   — 

/$-«'-  S>      | 

<       o 

/  p  io/es;  <o  from  eacfiEnch 


2  PAT  TERNS 
MATERIALS,:  , 

One  Steel  Bar  -  4'$  *HQ  «  6-6  long 
Three  Set  Screws  fy  xlfy' 


WROUGHT  IRON 


STEEL  CASTING 


STEEL  CASTING 
* 


k^yj/fc^i 


FIG.  26. — Design  for  Crucible  Holder  for  Locomotive-Frame  Welds. 


Don't  use  pin  grease  or  wood  in  place  of  wax  for  the  collar. 
Pin  grease  has  some  sulphur  in  it  and  we  all  know  how  un- 
desirable the  presence  of  sulphur  is  in  iron  or  steel.  Pin  grease 
and  wood  of  course  burn  out  in  the  preheating,  but  they  leave 
a  carbon  deposit  that  will  not  burn  off  but  will  bake  on. 

Don't  vary  the  dimensions  of  the  wax  collar.  Make  collars 
of  uniform  width  and  thickness  on  ail  sides,  thus  insuring  an 


356  GAS  TORCH  AND  THERMIT  WELDING 

even  distribution  of  heat.  In  the  case  of  welds  on  pedestal  legs 
cutting  down  the  thickness  of  the  collar  is  poor  policy.  Re- 
member that  the  weld  is  the  object  and  the  weld  will  not  be 
perfect  if  the  dimensions  of  the  collar  are  not  the  same  on 
all  sides. 

Don't  moisten  the  molding  material  too  much.  Have  it 
damp  enough  to  bind  under  the  natural  pressure  exerted  in 
closing  the  hand. 

Don't  use  a  molding  material  that  runs  to  slag  in  the  course 
of  preheating;  if  it  will  not  stand  the  preheating  torch  it  surely 
will  break  down  to  slag,  as  the  Thermit  steel  flows  into  it, 
and  a  mixture  of  slag  and  steel  is  not  at  all  desirable  and 
furthest  from  a  perfect  weld. 

Don't  forget  to  support  the  frame  and  mold  box  by  means 
of  blocks  or  jacks,  as  the  weight  of  the  rammed  mold  is  con- 
siderable and  will  sag  the  frame. 

Don 't  start  off"  the  preheater  with  too  strong  a  blast.  Take 
it  easy  at  the  start  and  increase  the  air  and  gasoline  as  the 
moisture  is  driven  out  of  the  molding  material.  In  this  way 
the  mold  will  not  be  cut  out  and  a  clean-looking  job  will  be 
the  result,  with  no  lumps. 

Don't  pour  the  Thermit  on  a  black-hot  frame;  heat  it  to 
a  good  workable  heat. 

Don't  use  crude  or  fuel  oil  to  preheat  the  frames.  In  start- 
ing the  burner  of  a  heater  using  either,  carbon  is  deposited 
on  the  frame  and  prevents  a  good  weld.  Heat  preferably  with 
gasoline  and  compressed  air.  If  gasoline  is  forbidden  use 
kerosene,  but  under  no  circumstances  use  crude  oil  or  fuel  oil. 

Don't  be  careless  in  plugging  the  crucible.  Careless  plug- 
ging results  in  premature  tapping,  and  this  latter  might  lead 
to  ugly  looking  or  defective  welds  due  to  the  imperfect  separa- 
tion of  slag  and  steel. 

Don't  guess  how  much  Thermit  to  use.  Consult  the  table 
of  instructions  and  you  will  not  go  astray. 

Don't  use  anything  but  railroad  Thermit  for  welding  a 
steel  or  wrought-iroii  section.  For  cast-iron  sections  use  cast- 
iron  Thermit. 

Don't  add  the  ignition  powder  to  the  charge  in  the  crucible 
until  ready  to  start  the  reaction.  It  is  advisable  to  suspend 
the  crucible  in  place,  charged  with  Thermit,  before  starting 


FUSION  WELDING  OF  HEAVY  SECTIONS  357 

to  preheat.  Everything  will  then  be  ready  for  pouring  at  the 
proper  time. 

Don't  tap  the  crucible  too  soon  after  starting  the  reaction. 
On  an  ordinary  frame  weld  taking  from  65  to  100  Ib.  of  Thermit 
permit  35  to  40  sec.  to  elapse  between  starting  the  reaction 
and  tapping  the  crucible.  This  to  insure  good  separation  of 
steel  and  slag. 

Don't  release  the  spreading  bar  or  jack  or  take  off  heat 
too  quickly  after  pouring.  It  is  best  to  hold  up  the  expansion 
for  two  to  three  hours  before  removing  jack  or  shutting  off 
heat. 

Don't  remove  the  mold  box  too  quickly  after  the  pour. 
Let  it  remain  in  place  over  night;  it  will  insure  the  frame 
cooling  off  slowly  and  naturally. 

Don't  forget  to  gather  up  all  the  materials  and  appliances 
after  completing  the  work.  Take  them  to  the  room  that  you 
ought  to  have  for  the  storage  of  this  material  and  it  will  be 
at  hand  when  you  want  to  make  use  of  it  again. 

Don't  get  excited — keep  cool. 

Don't  take  a  chance.  Be  sure  everything  is  right  as  you 
go  along.  There  is  no  such  thing  as  luck. 

Also  remember  that  the  riser  must  be  2^X4  in.  at  the  bot- 
tom and  3X4J  in.  at  the  top  and  not  less  than  14  in.  high 
where  clearances  will  admit.  In  the  case  of  welds  on  vertical 
members  two  risers  should  be  used,,  but  their  total  capacity 
need  not  be  greater  than  the  riser  for  which  dimensions  have 
been  given.  The  pouring  gate  must  be  not  less  than  1  in.  in 
diameter  at  the  bottom,  1J  in.  in  diameter  at  the  top  and  30  in. 
long.  Mold  boxes  should  be  made  of  3/10-in.  sheet  iron,  allow- 
ing for  at  least  4  in.  of  molding  material  on  all  sides  of  the 
Thermit  steel. 


CHAPTER  IV 
WELDING     CRANKSHAFTS,     MILL    PINION     TEETH,     ETC. 

We  will  now  take  up  the  welding  of  crankshafts,  mill 
pinions,  rudder-stocks  and  other  repairs  which  must  be  lined 
up  as  accurately  as  possible.  It  is  not  necessary  to  go  into 
details  as  to  the  exact  method  of  making  the  Thermit  welds, 
as  these  have  already  been  thoroughly  covered.  It  is  merely 
intended  to  go  into  the  question  of  allowances  for  contraction, 
causes  of  inaccuracies  in  alignment  after  welding,  effects  of 
mechanically  preventing  the  expansion  and  contraction  and 
other  possible  difficulties. 

Mechanically  preventing  the  contraction  of  a  weld,  inten- 
tionally or  otherwise,  is  a  common  fault  in  Thermit  welding 
and  can  be  prevented  only  by  constant  vigilance  on  the  part 
of  the  operator.  Most  operators  in  repairing  locomotive  frames, 
for  instance,  will  arrange  to  jack  the  sections  of  the  frame 
apart  or  separate  them  by  heating  the  adjacent  members  or 
in  some  similar  way  to  allow  for  the  contraction  which  they 
know  will  take  place  when  the  metal  in  the  weld  cools.  When, 
however,  the  Thermit  operator  is  confronted  with  the  problem 
of  welding  a  shaft  or  similar  part,  he  will  very  often  make 
the  mistake  of  strapping  the  shaft  as  tightly  as  possible  to 
a  bedplate  or  in  V-blocks,  which  will  prevent  the  weld  from 
contracting  if  the  clamps  are  efficient,  although  actually  allow- 
ing |  in.  or  1  in.  for  this  contraction.  One  particularly  bad 
case  is  reported  of  "preventing  contraction"  in  which  an 
experienced  operator  jacked  a  heavy  steel  section  of  a  rudder 
frame  apart  to  allow  for  contraction  in  a  broken  rib  8X4  in. 
and  then  proceeded  to  ram  the  jack  up  in  the  mold  box.  The 
result  of  course  was  that  the  section  cracked  alongside  of  the 
Thermit  weld  and  the  jack  had  to  be  cut  in  two  in  order  to 
remove  it.  But  in  crankshaft  welds  the  usual  result  of  efficient 
clamping  to  keep  the  pieces  in  line  will  be  the  formation  of 

358 


WELDING   CRANKSHAFTS,    MILL   PINION   TEETH,    ETC.     359 

holes  in  the  weld  which  in  all  probability  will  be  blamed  on 
the  Thermit,  a  new  crucible,  the  breaking  down  of  the  mold 
or  to  other  similar  causes.  Such  holes  can  usually  be  easily 
distinguished  from  ordinary  blowholes  by  the  fact  that  their 
axes  run  parallel,  or  nearly  parallel,  to  the  line  of  the  contrac- 
tion which,  in  the  case  mentioned  above,  is  the  axis  of  the 
shaft. 

To  show  how  prone  operators  are  to  make  this  mistake 
one  operator  who  ordinarily  would  carefully  release  the  clamps 
to  allow  for  the  contraction  of  a  shaft  weld  neglected  to  do  so 
in  welding  a  small  trunnion  on  the  end  of  a  heavy  steel  cross- 
head.  This  trunnion  was  defective  and  was  replaced  by  weld- 
ing a  piece  of  5-in.  shafting  onto  the  cross-head.  The  cross-head 
was  laid  on  a  bedplate  and  the  trunnion  was  set  up  in  position 
on  a  supporting  block  and  strongly  clamped  in  place.  The 
mold  was  rammed  and  the  weld  poured  in  the  usual  way  with 
the  result  that  holes,  or  shrink-holes,  occurred  parallel  to  the 
axis  of  the  trunnion. 

Defects  That  Frequently  Occur. — As  an  illustration  of  the 
formation  of  these  holes  prick  a  small  hole  in  an  elastic  band 
and  then  stretch  the  band.  The  hole  at  first  is  not  noticeable, 
but  it  will  be  very  noticeable  if  the  band  is  stretched.  The 
original  hole  corresponds  with  the  pores  that  occur  in  cast 
metal  and  the  elongated  hole  is  the  result  of  preventing  con- 
traction. A  similar  defect  may  be  caused  in  a  Thermit  weld 
by  having  a  riser  with  too  great  a  flare,  as  the  sand  in  the 
mold  tends  to  prevent  the  riser  from  pulling  in  toward  the 
weld.  In  this  case  of  course  the  holes  will  run  nearly  parallel 
to  the  axis  of  the  riser.  This  kind  of  defect  frequently  occurs 
and  is  difficult  to  overcome  where,  for  instance,  the  part  to 
be  welded  is  in  the  crankpin  of  a  shaft  and  where  the  slabs 
or  throws  are  quite  close  together.  In  such  a  case  if  the  sand 
is  rammed  tightly  between  the  slabs  it  will  prevent  the  con- 
traction of  the  pin  weld,  and  pull-holes  parallel  to  the  axis  of 
the  pin  will  be  the  result. 

All  of  these  defects  can  be  corrected  or  rather  prevented 
in  one  way  or  another.  In  the  cross-head  weld  previously 
mentioned  as  well  as  all  shaft  welds,  rudder-stocks,  etc.,  the 
lighter  part,  or  section,  should  be  carefully  supported  on  flat 
blocks'  so  that  it  will  be  stable  without  any  clamp  and  so  that 


360  GAS  TORCH  AND  THERMIT  WELDING 

it  can  be  moved  backward  and  forward  in  the  line  of  the  weld 
without  affecting  the  alignment.  A  strong  clamp  should  then 
be  set  in  place  to  hold  the  pieces  in  line  while  ramming  the 
mold,  but  should  be  removed  from  the  lighter  piece  before  pre- 
heating and  pouring.  In  repairing  a  break  in  a  small  section 
adjoining  two  heavy  sections  it  might  even  be  advisable  to 
support  one  or  both  of  the  heavy  sections  on  rollers,  as  their 
weight  alone  might  very  likely  pull  holes  in  the  weld. 

In  welding  crankshafts  it  is  customary  and  best  to  align 
the  shafts  on  V-blocks.  These  V-blocks  are  heavy  pieces 
accurately  machined  and  slide  in  a  machined  slot  of  a  heavy 
bedplate.  The  V-blocks  should  be  spaced  along  the  slot  of 
the  bedplate  so  as  to  correspond  with  the  journals  of  the 
crankshaft.  Parallel  to  the  main  slot  of  the  bedplate  and  on 
either  side  of  it  are  smaller  slots  similar  to  those  in  planing- 
machine  beds.  The  heads  of  the  holding-down  bolts  are  placed 
in  these  slots  opposite  the  V-blocks  and  a  short  bar  or  channel 
placed  across  the  shaft  and  clamped  down  by  means  of  nuts 
on  the  holding-down  bolts. 

The  V-blocks  should  be  so  placed  on  the  main  journals  that 
the  shaft  can  slide  at  least  £  in.  either  way  parallel  to  its  axis 
without'  a  shoulder  or  crank  throw  striking  any  part  of  the 
V-blocks.  Experience  has  shown  that  crankshafts  usually 
break  in  a  main  journal  or  in  a  pin  journal  close  to  a  crank 
throw  or  slab,  or  the  break  may  occur  in  the  slab  itself.  It 
is  usually  desirable  to  line  up  the  shaft  with  the  throws  in  a 
horizontal  position.  Let  us  imagine  a  shaft  with  a  break  in 
one  slab  or  throw  close  to  the  pin  journal  and  the  shaft  lined 
up  in  V-blocks  with  the  throws  horizontal,  the  necessary  gap 
cut  out  and  the  wax  and  mold  in  place  ready  to  preheat.  The 
operator  would  probably  have  a  great  deal  of  trouble  trying 
to  allow  for  the  contraction  and  would  probably  attempt  to 
do  this  by  shifting  one  part  of  the  shaft  about  J  in.  along  in 
the  V-block  and  would  place  various-sized  shims  in  the  V-blocks 
to  allow  for  the  contraction  along  the  line  of  the  slab. 

Inaccuracy  of  Alignment  Explained. — It  would  all  be  simple 
enough  if  after  pouring  the  weld  the  shaft  would  remain 
dormant  until  the  weld  started  to  contract  when  the  shims 
could  be  removed  from  one  side  and  placed  on  the  opposite 
side  to  allow  the  slab  to  contract,  but  from  measurements  that 


WELDING   CRANKSHAFTS,    MILL  PINION  TEETH,   ETC.     361 

have  been  taken  it  has  been  found  that  immediately  after  pour- 
ing the  weld  there  is  a  great  deal  of  force  exerted,  as  though 
a  jack  were  placed  between  the  sections  that  were  fractured. 
This  is  of  course  caused  by  the  intense  heat  of  the  Thermit 
steel  conducting  into  the  parts  of  the  shaft  adjacent  to  the 
weld,  causing  them  to  expand.  One  might  suppose  that  there 
would  be  no  great  force  exerted  while  the  metal  in  the  weld 
was  molten,  but  this  can  be  explained  by  the  fact  that  the 
riser  and  pouring  gate  have  become  sufficiently  sluggish  to 
hold  the  more  liquid  metal  below  from  forcing  upward.  How- 


6*—-->\  6 Wanted 


Finish  all  over 


FIG.  27.— Design  of  V-Bloeks   for   Welding  Crankshafts. 

ever,  the  fact  remains  that  the  parts  of  the  shafts  are  strongly 
forced  apart  so  as  to  slightly  tilt  the  V-blocks  and  raise  the 
shaft  out  of  line.  t 

This  may  explain  why  the  inaccuracy  in  alignment  is  not 
in  the  direction  of  the  contraction  of  the  weld  but  almost  at 
right  angles  to  it.  In  a  great  many  cases  this  tendency  to 
separate  will  shift  the  parts  of  the  shaft  horizontally  as  much 
as  J  in.  and  as  the  V-blocks  resist  this  they  are  tilted  by  the 
force  and  the  shaft  thrown  out  of  line. 

It  may  be  hours  before  any  considerable  contraction  sets  in, 


362  GAS  TORCH  AND  THERMIT  WELDING 

and  by  this  time  the  shaft  has  been  permanently  set  out  of 
line.  Heating  the  opposite  slab  will  slightly  counteract  this, 
but  not  sufficiently,  because  the  heat  conducted  from  the 
Thermit  steel  will  expand  one  slab  a  great  deal  more  than 
any  possible  preheating  on  the  opposite  slab. 

Crankshafts  that  are  broken  in  such  a  way  that  they  can 
be  lined  up  with  the  throws  in  a  vertical  position  will  be  almost 
as  far  out  of  line  because  the  sudden  expansion  of  the  adjacent 
parts  will  have  to  shift  part  of  the  shaft  and  even  sometimes 
lift  it  partly  out  of  the  V-blocks,  £nd  this  force  is  being  exerted 
through  molten  or  perhaps  plastic  metal  so  that  a  certain 
amount  of  upsetting  will  naturally  take  place. 

V-Blocks  for  Holding  Shafts. — In  order  to  overcome  these 
important  defects  the  special  V-blocks  shown  in  Fig.  27  will 
allow  a  horizontal  motion  after  the  mold  is  rammed.  If  then 
the  proper  allowance  for  contraction  is  made  the  shaft  should 
come  back  into  line  because  the  force  tending  to  separate  the 
fracture  will  not  be  resisted  and  will  be  subsequently  offset 
by  an  equal  contraction,  On  the  other  hand  such  V-blocks 
will  permit  of  watching  the  contractions  of  the  shaft  so  that 
different  allowances  can  be  made  on  the  next  shaft  if  necessary. 

These  V-blocks  should  be  made  in  such  a  way  that  they 
will  be  divided  in  two  parts  horizontally.  The  upper  and  lower 
parts  should  each  have  divisions,  accurately  marked  on  them 
next  to  the  dividing  line,  the  central  division  being  longer 
and  heavier  than  the  rest.  When  the  two  parts  of  the  V-blocks 
are  central  on  each  other,  accurately  turned  pins,  preferably 
tapered,  may  be  inserted  in  reamed  holes  passing  through  the 
two  lugs  so  as  to  securely  fasten  them  together.  This  locates 
accurately  the  central  position  where  the  shaft  is  to  be  lined 
up  "in  line."  Where  a  horizontal  contraction  is  to  be  allowed 
for,  the  pin  should  be  left  out  of  certain  V-blocks  and  the 
parts  of  these  V-blocks  slightly  shifted  on  each  other  if  neces- 
sary. If  the  V-block  pins  are  not  in  place  the  holding  down 
bolts  can  be  relied  upon  to  hold  the  shaft  in  a  desired  position 
during  the  ramming  of  the  mold.  When  the  preheating  is 
started  these  bolts  should  of  course  be  removed  and  the  shaft 
allowed  to  move  freely.  Another  advantage  of  this  type  of 
V-block  is  that  flat  shims  can  be  placed  between  the  halves 
of  the  V-blocks  to  allow  for  different  journal  diameters  instead 


WELDING  CRANKSHAFTS,   MILL  PINION   TEETH,   ETC.    363 

of  placing  the  shims  on  the  slanting  face  of  the  V-blocks.  The 
thickness  of  the  shims  will  of  course  be  just  half  the  difference 
in  the  diameters  of  the  journals. 

In  allowing  for  contraction  of  a  Thermit  weld  it  must  be 
remembered  that  the  actual  contraction  of  the  small  amount 
of  Thermit  steel  in  the  space  between  the  pieces  is  almost 
negligible,  whereas  the  actual  contraction  of  the  weld  may 


PIG.  28. — Two-Throw  Crankshaft — Fracture  Cut  Away  for  Welding. 


FIG.  29, — Two-Throw  Crankshaft  Welded — Repair  Made  in  72  Hours. 

vary  from  T/i«  to  Y4  in.  This  is  due  to  the  fact  that  during 
the  preheating  operation  the  ends  of  the  pieces  at  the  fracture 
expand  or  approach  each  other  by  the  amount  of  the  expansion 
of  the  adjacent  parts  by  the  preheating.  For  instance,  if  the 
fracture  is  opened  up  J  in.  to  allow  for  the  contraction  and 
the  expansion  of  the  parts  during  the  preheating  approach  each 
other  almost  3/4  in  (perhaps  Yel  in.  less)  the  parts  should 


364 


GAS  TORCH  AND  THERMIT  WELDING 


be  almost  exactly  in  line  after  welding.  In  welding  large  sec- 
tions slightly  greater  allowances  for  contraction  should  be 
made  than  in  smaller  ones,  because  to  bring  the  fracture  to 
the  proper  heat  takes  a  longer  time  and  consequently  the  heat 
" soaks"  further  along  the  parts,  causing  a  greater  expansion 
and  a  greater  tendency  to  close  up  the  distance  between  the 
fractures. 

A  large  two-throw  crankshaft  previous  to  welding  is  shown 


FIG.  30. — Fracture  in  Web  Cut  Away  for  Welding  a  Crankshaft. 


FIG.  31. — Welded  in  6*  In.  Crankshaft  Broken  in  the  Web. 


in  Fig.  28.  This  same  crankshaft  after  welding  is  shown  in 
Fig.  29.  A  6J  in.  crankshaft  broken  in  the  web  is  shown  in 
Fig.  30  and  the  finished  weld  in  Fig.  31. 

How  to  Locate  Minute  Cracks  in  Crankshafts  or  Other 
Parts. — In  the  course  of  welding  crankshafts  and  other  im- 
portant work  it  is  often  found  that  while  the  part  to  be  welded 
is  broken  clear  through  there  are  other  minute  hairline  cracks 


WELDING  CRANKSHAFTS,   MILL   PINION  TEETH,   ETC.     365 

near  by  which  are  sure  to  give  trouble  later.  It  is  probable 
that  the  strain  thrown  on  the  part  when  the  break  occurs 
is  often  sufficient  to  start  these  small  cracks.  They  may  also 
be  caused  by  strains  in  the  metal  from  improper  treatment  in 
the  first  place,  and  which  may  have  been  responsible  for  the 
first  break. 

In  any  case,  however  they  may  have  been  caused,  the  proper 
thing  to  do  is  to  locate  these  cracks  and  so  weld  the  parts 
as  to  eliminate  them.  As  they  are  many  times  so  minute  as 
to  be  invisible  to  the  naked  eye  some  other  means  must  be 
found  to  locate  them.  A  very  efficient  method  is  to  paint  the 
entire  section  with  a  mixture  of  whiting  and  alcohol.  The  whit- 
ing and  alcohol  should  be  mixed  so  as  to  form  a  good  white 
paint,  but  not  too  thin.  This  dries  quickly  and  becomes  dis- 
colored by  the  grease  or  dirt  in  the  very  fine  cracks,  so  that 
these  cracks  show  up  very  distinctly.  Since  it  is  the  oil  or 
dirt  in  these  cracks  that  causes  them  to  show  so  clearly  on 
the  white  paint  it  is  not  a  good  method  to  detect  cracks  in 
a  new  piece.  The  part  to  be  painted  should  of  course  be  cleaned 
of  all  the  dirt  and  grease  on  the  surface.  It  is  a  conservative 
estimate  to  say  that  probably  one-third  of  all  crankshafts  will 
be  found  to  contain  additional  cracks  other  than  where  the 
break  is  visible.  If  these  are  not  found  and  remedied  the 
chances  are  that  they  will  develop  into  real  breaks  later. 

Welding  New  Teeth  in  Large  Pinions  to  Replace  Teeth 
Broken  Out. — The  Thermit  process  is  coming  into  more  and 
more  general  use  in  large  steel  works  and  rolling  mills  for 
welding  teeth  in  heavy  pinions,  as  it  can  be  relied  on  to  give  a 
permanent,  efficient  and  economical  repair  in  the  case  of  these 
very  heavy  sections. 

The  following  instructions  cover  a  method  which  has  been 
in  use  for  several  years,  and  if  they  are  carefully  followed  a 
satisfactory  repair  is  assured.  Many  piniohs  weighing  up  to 
17  tons  have  been  repaired  in  this  way  and  are  now  doing 
service. 

The  repairs  usually  consist  of  replacing  teeth  or  parts  of 
teeth  which  have  broken  out.  They  are  peculiar  in  that  the 
tooth  is  a  comparatively  small  projection  on  an  extremely 
heavy  steel  casting.  For  this  reason,  if  the  repair  were  at- 
tempted by  the  ordinary  method,  i.e.,  if  the  casting  were  pre- 


366  GAS  TORCH  AND  THERMIT  WELDING 

heated  at  the  weld  only  as  covered  in  previous  instructions 
for  making  Thermit  welds,  the  heat  would  be  carried  away 
into  the  castings  so  quickly,  especially  during  the  interval  of 
removing  the  preheating  burner  and  tapping  the  crucible,  that 
in  most  cases  a  poor  weld  would  result.  Everything  possible 
must  therefore  be  done  to  conserve  the  heat  at  the  weld,  and 
to  do  this  efficiently  it  is  necessary  that  the  whole  pinion 
should  be  heated  to  a  red  heat.  This  may  be  done  by  bricking 
in  the  heaviest  part  and  preheating  it  by  means  of  oil  or  gas 
burners  conveniently  placed  while  the  part  to  be  welded  is 
being  preheated  in  the  regular  way.  The  Thermit  company's 
flaming-burner  preheater  attachments  are  admirably  adapted 
to  this  preheating  work,  as  they  give  an  extremely  hot  flame 
which  may  be  adjusted  to  suit  the  conditions.  Care  should 
be  taken,  however,  to  bring  up  the  heat  slowly,  as  otherwise 
there  is  danger  of  cracking  the  pinion. 

In  making  all  welds  where  a  relatively  small  amount  of 
Thermit  steel  is  to  be  added  to  a  heavy  steel  casting  or  where 
one  or  both  of  the  parts  to  be  joined  is  considerably  heavier 
and  larger  than  the  Thermit  steel  part  it  is  necessary  to  take 
special  precautions  to  secure  thorough  amalgamation  of  the 
Thermit  steel  with  the  heavier  part,  especially  at  the  extreme 
edges  of  the  line  of  junction  where  in  service  the  greatest 
strain  will  come.  The  slightest  imperfection  at  this  line  of 
junction  or  extreme  fiber  will  cause  a  tear  to  start  in  service 
which  will  cause  a  fracture  of  the  welded  part.  A  perfect  weld 
on  this  extreme  fiber  is  made  more  difficult  by  the  fact  that 
the  metal  in  the  weld  always  shrinks  a  little  more  than  the 
white-hot  steel  of  the  pinion  due  to  the  slight  difference  in 
shrinkage  between  molten  steel  and  white-hot  steel.  It  is 
necessary  therefore  that  the  fusion  be  obtained  for  a  consider- 
able depth  even  at  the  extreme  edge  of  the  Thermit  steel. 
Fusion  at  this  point  is  more  difficult  because  the  heat  of  the 
Thermit  steel  comes  from  one  side  only  and  not  from  all 
sides  as  it  does  near  the  center  of  the  weld. 

For  all  these  reasons  it  is  desirable  to  increase  as  far  as 
possible  the  surface  exposed  to  the  Thermit  steel  in  the  width 
cf  the  weld.  This  at  the  same  time  produces  edges  or  corners 
which  melt  more  readily  and  thus  aid  in  the  fusion.  These 
edges  may  be  readily  produced  by  cutting  out  a  groove  or 


WELDING  CRANKSHAFTS,  MILL  PINION  TEETH,  ETC.     367 

slot  in  the  main  body  of  the  pinion  at  the  center  part  of  the 
root  of  the  tooth  broken  out.     This  slot  should  be  half  the 


/brt("j0/pe..^-J\  ^PreheaterHose 
V    Connection 


W-Outer  Pipe  to  protect 
inner  Pipe  from  Meat 


TEMPLET  IN  FORMING  NEW  TOOTH  IN  WAX      Li ftina  Plate  Y^U^S* 
A  should  Pipe  ^      ° 

M  burn  off 

DETAIL  or  BVRHEIf 


bewellcoa-tedwith 
a  strong  Silica  Vtash 


_  -FLAME 

Preheating  Cope 

if  Necessary  to  use 

H 


!<-„..  X  — X 


PI  an  of  PartsTB" 
G 


'Filled  with  fire  Clay 


PATTERN  FOR  ROLL-NECK 
REPAIRING 

JL 


Hook  to  be  used  in  Sand 

Case  Pipe'A  "should  Core  •, 

come  loose  from  i % 

Plate,  when  removing  L si 

Burner  insert  hook 
in  Vent  Holes  tolift 

out  Plate  PLUG  FOR  OVERFLOW  GATE 

Two  wanted  *J 


"-Bolt 


Pipe 


FIG.    32. — Designs    for    Patterns    and    Heating    Apparatus    for    Repairing 

Steel  Pinions. 


width  of  the  tooth  in  depth  and  also  in  width,  i.e.,  if  the  tooth 
to  be  welded  in  is  6  in.  wide  at  its  root  the  slot  should  be 
made  3  in.  wide  by  3  in.  deep.  The  most  economical  way  to 


368  GAS  TORCH  AND  THERMIT  WELDING 

cut  this  slot  is  to  place  the  pinion  on  a  planer  and  machine 
it  out. 

The  cutting  of  such  a  slot  also  serves  to  bring  the  line 
of  junction  between  the  Thermit  steel  and  the  metal  of  the 
pinion  well  into  the  body  of  the  pinion  so  that  a  strong  and 
efficient  weld  is  assured. 

After  the  slot  has  been  cut,  the  pinion  in  the  vicinity  of 
the  weld  should  be  carefully  cleaned  and  then  mounted 
vertically  for  the  welding  operation.  In  this  mounting  great 
care  should  be  taken  that  the  pinion  is  properly  supported  so 
that  there  will  be  no  danger  of  its  settling  under  the  added 
weight  of  the  mold  box.  This  can  be  accomplished  in  the 
following  manner: 

First  dig  a  hole  in  the  ground  the  proper  size  to  receive 
the  neck  of  the  pinion.  Then  lay  two  T-rails  across  the  top 
of  the  hole  so  that  they  will  come  underneath  the  shoulder  of 
the  pinion.  If  the  ground  is  not  sufficiently  hard  to  properly 
support  the  T-rails  steel  plates  can  be  placed  underneath  in 
order  to  prevent  the  rails  from  settling  into  the  ground. 

Making  the  Wax  Tooth  Pattern. — With  the  pinion  properly 
supported  in  this  manner  the  next  step  is  to  provide  the  wax 
pattern  for  the  new  tooth.  This  can  best  be  done  by  con- 
structing a  rough  wooden  box  a  little  larger  than  the  tooth 
in  question.  Place  this  against  the  pinion  where  the  new  tooth 
is  to  be  added  and  lute  around  the  edge  of  the  box  with  fire 
clay.  Next  fill  this  box  completely  with  molten  wax.  When 
the  wax  has  set  remove  the  box  and  shape  to  proper  form 
by  means  of  a  templet  as  shown  in  A,  Fig.  32. 

This  templet  should  be  made  from  J-in.  steel  plate  and 
the  outline  of  the  teeth  cut  into  it  by  using  three  good  teeth 
in  the  pinion  as  a  guide.  The  center  tooth,  however,  which 
will  be  the  guide  for  the  tooth  to  be  welded  in,  should  be  cut 
V32  in-  larger  all  around  so  as  to  allow  for  the  contraction 
of  the  Thermit  steel  tooth.  The  two  outside  teeth  of  the  templet 
engage  with  the  teeth  on  each  side  of  the  wax  pattern,  and 
therefore  when  this  templet  is  moved  up  and  down  it  will 
cut  the  wax  to  proper  shape  and  also  assure  that  the  new 
tooth  is  welded  on  in  proper  pitch. 


WELDING  CRANKSHAFTS,    MILL   PINION   TEETH,   ETC.    369 


ANOTHER  METHOD 

One  disadvantage  of  this  method  of  making  the  wax  core 
is  that  if  the  adjacent  teeth  are  considerably  worn  the  new 
tooth  will  not  conform  to  their  shape  unless  the  templet  is 
juggled  considerably  when  shaping  the  wax  pattern.  A  newer 
method  has  recently  been  developed  by  F.  N.  Keithley  and 
used  with  success.  This  method  gives  a  cast  tooth  of  the  same 


Tooth  broken  ou 


Scrape  off !%  from  Sand 

C 
Wax  cut  up  into  small  Cubes 


Board  over  Shroud  Ring 
Clay  L  uting 


Height  of  Tooth 


• 


BOARD  USED  AS  BOTTOM  OF 
SAND  CORE 

E 


FIG.  33. — Recently  Developed  Method  of  Making  Wax  Tooth  Pattern. 

approximate  shape  as  the  others  in  the  pinion,  even  if  con- 
siderably worn,  which  is  an  obvious  advantage. 

Referring  to  Fig.  33  the  broken  tooth  is  slotted  out  as  in 
the  previous  method  and  the  adjacent  teeth  are  cleaned  and 
scraped.  With  the  pinion  in  a  horizontal  position  wooden 
strips  are  fitted  to  the  bottoms  of  the  tooth  spaces,  as  shown 
at  the  left  in  C.  Lag  screws  are  screwed  into  these  for  handling 
purposes.  Further  details  of  the  strips  are  shown  at  E.  A 


370  GAS   TORCH  AND  THERMIT  WELDING 

mixture  of  two  parts  building  sand  to  one  of  fire  clay  is  sifted 
through  a  No.  4  mesh  riddle  and  moistened  a  little  more  than 
for  ramming  a  mold.  If  this  mixture  does  not  draw  well  more 
fire  clay  may  be  added.  The  mixture  is  pressed  between  the 
model  teeth  on  top  of  the  board  strips,  as  shown  at  the  right 
in  C.  The  mixture  is  rammed  in  firmly  to  a  point  J  in.  above 
the  top  of  the  tooth  on  the  side  for  the  wax  pattern,  as  in- 
dicated at  C  and  at  F.  The  idea  is  to  provide  sufficient  height 
of  wax  to  allow  for  shrinkage. 

After  the  two  parts  are  rammed  they  are  lifted  out  and 
laid  .carefully  on  a  board.  One-fourth  of  an  inch  of  material 
is  then  carefully  scraped  off  of  the  side  of  each  piece  that 
does  not  come  in  contact  with  the  wax,  and  the  surfaces  are 
slicked.  This  is  to  allow  for  shrinkage  of  both  wax  and 
Thermit  steel.  The  two  pieces  are  now  placed  in  position  as 
shown  at  D.  Weights  should  be  placed  partly  on  the  pieces 
and  partly  on  the  adjacent  teeth  to  hold  the  pieces  in  place. 
The  ends  are  then  luted  with  fire  clay  and  the  space  filled 
with  small  pieces  of  wax.  The  melted  wax  is  then  poured  in, 
taking  care  not  to  have  it  too  hot,  as  it  will  eat  into  the  sand 
if  it  is. 

The  mold  parts  in  position  and  the  wax  poured  are  shown 
at  D.  If  the  pinion  is  shrouded  the  wax  pattern  for  the  shroud 
can  be  put  on  at  the  same  time  that  the  wax  tooth  is  formed. 
It  is  only  necessary  to  roll  a  clay  rod  about  1  in.  in  diameter 
and  lay  it  against  the  pinion  3  in.  away  all  around  from  the 
space  cut  in  the  shroud.  Back  this  up  with  a  board  large 
enough  to  extend  above  the  top  of  the  tooth  and  lute  as  in- 
dicated at  B. 

When  the  wax  pattern  is  finished  the  mold  box  should  be 
placed  in  position  and  securely  clamped  to  the  pinion,  the 
clamps  to  be  in  a  position  so  as  not  to  come  in  contact  with 
the  fire  when  the  pinion  is  being  preheated. 

This  mold  box  should  be  wide  enough  to  take  in  twp  teeth 
on  each  side  of  the  tooth  to  be  welded.  Now  ram  up  the  mold 
box,  allowing  for  a  preheating  gate,  a  pouring  gate  and  a 
riser  in  accordance  with  instructions  already  given.  When 
this  is  completed  construct  a  brick  furnace  around  the  exposed 
part  of  the  pinion  and  about  2  in.  away  from  the  teeth.  Next 
place  a  sheet-iron  casing  around  the  exposed  neck  on  top. 


WELDING   CRANKSHAFTS,    MILL  PINION   TEETH,   ETC.    371 

This  casing  should  be  6  in.  larger  in  diameter  than  the  neck 
and  about  4  in.  higher.  Now  ram  sand  between  the  casing 
and  the  neck  and  cover  the  top  with  a  layer  of  sand  4  in.  thick. 
In  this  way  the  entire  pinion  is  insulated. 

Preheating. — The  next  step  is  the  preheating.  Place  a 
burner  at  the  bottom  of  the  brick  furnace  as  shown  in  Fig.  34, 
and  start  with  a  very  mild  heat.  This  is  to  avoid  heating 


FlG.  34. — Mold   Box,   Brick   Furnace  and  Crucible   in   Position  and   Pinion 

Being  Preheated. 

the  pinion  too  quickly,  thus  causing  internal  strains  which 
might  result  in  cracking  the  pinion.  After  the  pinion  has  been 
thoroughly  soaked  with  heat  the  fire  can  be  increased  to  a 
good  sharp  heat  so  as  to  bring  the  entire  pinion  to  a  good 
blood  red  or  about  1200  deg.  Fahrenheit. 

While  the  heating  is  in  progress,  as  shown  in  the  rear  view, 
Fig.  35,  place  an  automatic  crucible  of  the  proper  size  to  hold 
the  Thermit  charge  in  position  over  the  pouring  gate  and 


372 


GAS  TORCH  AND  THERMIT  WELDING 


charge  with  the  welding  portion  of  Thermit.  In  case  of  very 
large  welds  it  is  sometimes  necessary  to  use  two  crucibles  and 
provide  two  pouring  gates  in  the  mold. 

Repairs  of  this  kind  usually  require  anywhere  from  350 
to  over  1000  Ib.  of  Thermit, 


FIG.    35. — Rear    View    Showing    Preheating    of    Body    of    Pinion    in   Brick 

Furnace. 

In  special  cases  it  is  advisable  to  make  up  a  special  steel 
mixture  of  essentially  the  same  analysis  as  that  of  the  pinion. 

Continue  heating  in  the  brick  furnace  until  the  Thermit 
steel  has  cooled  to  about  the  same  temperature  as  the  body 


WELDING  CRANKSHAFTS,   MILL  PINION   TEETH,   ETC.    373 


of  the  pinion,  then  remove  the  burner  from  the  furnace,  take 
off  a  few  of  the  top  bricks  and  fill  in  between  the  bricks  and 
the  pinion  with  dry  sand,  thereby  protecting  the  pinion  com- 
pletely from  the  air  currents. 


FIG.  36. — Finished  Weld,  Showing  Metal  in  Pouring  Gate  and  Kiser. 

The  pinion  should  be  allowed  to  cool  slowly  in  this  mold 
for  at  least  six  or  seven  days  so  as  to  thoroughly  anneal  the 
metal  in  the  entire  piece.  The  mold  can  then  be  dismantled, 
the  weld  trimmed  and  the  pinion  will  be  ready  for  service. 
A  pinion  previous  to  trimming  is  shown  in  Fig.  36. 


CHAPTER   V 

WELDING   NEW   NECKS    ON   LARGE    STEEL   PINIONS 
AND  OTHER  HEAVY  WORK 

Frequent  breakages  of  heavy  pinions  in  steel  plants  have 
resulted  in  the  development  of  a  very  ingenious  adaptation 
of  the  Thermit  process  for  their  repair.  Obviously  the  casting 
on  of  a  new  neck  entirely  out  of  Thermit  steel  would  be  a 
very  expensive  operation  and  it  would  also  be  costly  and  diffi- 
cult to  turn  up  a  new  piece  of  steel  and  weld  it  on  to  the 
original  section,  as  the  weld  would  be  a  very  large  one  to 
make.  Experience  has  shown,  however,  that  the  intense  heat 
of  the  reaction  can  be  utilized  for  the  purpose  of  bringing  the 
broken  surface  of  the  pinion  to  a  fusing  temperature,  at  which 
time  a  supply  of  liquid  steel  can  be  poured  in  from  the  ladle, 
and  this  will  unite  with  the  original  body  of  the  pinion  to 
form  a  new  neck  thoroughly  amalgamated  with  the  rest  of 
the  piece. 

Briefly  the  operation  consists  in  constructing  a  mold  around 
the  broken  section  so  as  to  permit  of  casting  on  a  new  neck 
to  replace  the  one  broken  off.  The  original  section  is  then 
preheated  to  red  heat  by  means  of  gasoline  or  oil  burners, 
after  which  Thermit  steel  from  a  crucible  is  allowed  to  flow 
over  the  fractured  surface  to  a  depth  of  1  in.  This  completes 
the  heating  operation  and  brings  the  surface  of  the  roll  to 
the  melting  point.  A  supply  of  liquid  steel  from  a  ladle  is 
then  tapped  into  the  mold  and  allowed  to  wash  through  and 
overflow  into  an  ingot  mold  so  as  not  to  be  wasted.  The 
overflow  gate  may  then  be  closed  and  the  mold  filled  to  the 
top  with  steel.  Detailed  instructions  for  these  various  opera- 
tions follow,  but  it  is  recommended  that  if  the  process  is  to 
be  used  for  the  first  time  for  such  repairs  an  experienced 
engineer  should  be  obtained  to  supervise  the  first  welds  and 
give  personal  instructions  for  executing  this  class  of  work. 

374 


WELDING   NEW   NECKS  ON   LARGE  STEEL  PINIONS     375 

The  instructions  given  here  have  been  written  more  especially 
for  the  purpose  of  acting  as  a  guide  for  a  reference,  and  while 
we  hope  that  there  are  sufficiently  adequate  and  complete  to 
enable  anybody  to  make  these  welds,  the  personal  supervision 
and,  instructions  of  an  experienced  engineer  are  much  to  be 
preferred. 

Two  Methods  of  Working. — We  give  two  methods  for 
executing  these  repairs.  The  first  method  which  follows  is 
undoubtedly  the  safest  and  surest  method  to  use,  but  it  involves 
considerably  more  trouble  and  expense  than  the  second  method. 
We  can  recommend  it  strongly,  however,  and  believe  it  would 
be  to  the  interests  of  steel  plants  having  much  of  this  work 
to  do  to  equip  themselves  properly  to  follow  out  this, method. 


FIG.  37. — Sawing  Off  End  of  Neck  Previous  to  Welding  on  a   New  One. 

Before  undertaking  a  pinion  repair  the  broken  end  should 
be  cut  off  square,  as  shown  in  Fig.  37,  so  as  to  form  a  level 
surface  when  the  roll  stands  in  a  vertical  position.  The  object 
of  this  is  to  p'ermit  of  a  uniform  covering  of  Thermit  steel 
over  the  entire  surface  to  be  welded.  If  the  break  is  in  the 
pods,  cut  off  2  in.  below  the  point  where  the  pod  joins  the 
neck.  If  when  the  neck  is  cut  off  it  should  be  found  to  contain 
any  pipes  or  cavities  these  should  be  bored  out  and  steel  plugs 
turned  to  a  driving  fit  and  driven  into  the  cavities  at  least 
5  in.,  care  being  taken  that  the  plugs  are  driven  in  even  with 
the  surface  on  the  end  of  the  neck. 

Another  and  better  method  is  to  dry  out  the  inside  of  the 
cavity  by  heating  and  then  fill  with  liquid  steel.  This  will 
eliminate  any  danger  of  the  -Thermit  metal  melting  the  plug 


376 


GAS  TORCH  AND  THERMIT  WELDING 


and  running  into  the  cavity,  which  might  cause  a  violent  and 
dangerous  eruption  of  the  steel.  Clean  off  all  dirt  and  grease 
at  least  20  in.  from  point  of  weld. 


FROM  FUEL  TANK 


Secti  on   A-A 

Foundation  to  su't  condition  of  ground  etc 
In  all  cases  see  tnatmO'C*  >s  supported 

on  roll  independent  of  f  100^ 
S'ze  and  number  of  nnoid  boxes  to  sui+  roll 


hole  to  be  plugged  after 

•mi  t  steel  is  washed  out 


FLOORLINE 


Roll  to  be 
strongly 
shorecffrom 
sides  of  pit 


FIG.  38. — A  Design  for  a  Permanent  Pit  for  Welding  Necks  on  Large 
Rolls  and  Pinions.  If  Desired  a  Removable  Fire-Brick  Partition  May 
Be  Used  Between  Roll  or  Pinion  Pit  and  the  Ingot  Mold  Pit. 

A  riser  pattern  should  be  provided,  undercut  as  shown  in 
Fig.  32-D,  also  a  pouring  gate  and  overflow  gate  pattern. 


WELDING   NEW  NECKS  ON   LARGE  STEEL  PINIONS      377 

The  riser  pattern  should  be  3  in.  larger  in  diameter  than 
the  pinion  neck,  and  at  the  lower  part,  where  it  joins  the  neck, 
it  should  taper  as  shown.  Where  the  operation  requires  the 
casting  of  pods  a  special  pattern  should  be  made  having  the 
shape  of  the  pinion  neck  with  these  pods.  This  pattern,  like 
the  riser  pattern  mentioned  before,  should  be  larger  in  diameter 
than  the  pinion  neck  and  should  taper  at  the  bottom.  The 
pattern  should,  if  necessary,  be  made  in  sections  so  as  to  allow 
of  being  withdrawn  from  the  mold. 

Foundation  and  Heating  Arrangements. — Heavy  circular 
cast-steel  mold  flasks  should  be  provided,  the  same  as  are  used 
in  steel-foundry  practice.  In  the  absence  of  these  flasks  suit- 
able ones  can  be  made  of  £-in.  steel  plate.  The  bottom  flask 
should  be  divided  and  bolted  together  s.o  that  it  can  be  removed 
without  trouble,  as  it  is  much  easier  to  tear  down  the  mold 
after  this  flask  is  removed  than  before. 

In  undertaking  repairs  on  these  pinions  it  is  recommended 
that  a  special  pit  be  constructed  as  shown  in  Fig.  38.  It  is 
of  the  utmost  importance  when  constructing  the  pit  to  provide 
a  good  foundation  for  the  bottom  pf  the  pit.  It  has  been 
found  in  many  cases  that  steel  plants  are  built  on  low  and 
marshy  ground,  therefore  when  a  pit  is  dug  the  ground  is  apt 
to  be  soft  and  many  times  water  seeps  in.  For  this  reason 
the  design  in  Fig.  39  is  shown.  However,  unless  precautions 
are  taken  to  provide  a  good  foundation  heavy  pinions  are  apt 
to  settle  before  the  welding  operation  is  completed.  This  is 
liable  to  cause  a  loss  of  the  repair  and  sometimes  a  serious 
explosion  might  result  caused  by  the  hot  metal  coming  in 
contact  with  moisture.  When  an  adequate  foundation  has 
been  provided  set  the  pinion  and  the  ingot  mold  in  place  and 
brace  them  strongly  to  the  sides  of  the  pit. 

Arrange  the  heating  burners  which  may  use  gas,  gasoline 
or  kerosene.  This  arrangement  is  shown,  although  the  com- 
plete connection  to  the  fuel  supply  is  not. 

Constructing  the  Mold.— Construct  the  mold,  as  shown,  of 
sharp  silica  sand  and  fire  clay.  The  usual  proportions  of  the 
mixture  are  three  parts  of  sand  to  one  of  clay,  but  this  varies 
according  to  the  sand  and  clay  used.  Coat  the  mold  with  a 
good  steel  wash  and  drive  in  nails  or  chaplets  to  hold  the  sand 
in  position. 


378 


GAS  TORCH  AND  THERMIT  WELDING 


Attach  the  runners  at  the  proper  points  and  ram  them  with 
the  same  material,  being  careful  to  arrange  the  runner  for 
the  Thermit  exactly  as  shown,  that  is,  the  runner  gate  is  so 


FROM  FUEL  TANK 


FROM  FUEL  TANK 


TROUGH 


Section  A-A 


hole  to  be 
rr~*plug(ied 

\<oiffcr  thermit 

steels 

'  washed 


Foundation  to  suit 
condition  of  ground  etc 
In  a  1 1  coses  see  that 
mold  is  supported  on 
roll  independent  of  floor. 
Size  end  number  of  mold 
boxes  to  suit  roll 


Roll  to  be 
strongly 
shorecffrom 
sides  -..-. 


FIG.  39. — Method  of  Welding  Eoll  Necks  Without  Digging  a  Pit. 

placed  that  when  the  Thermit  steel  has  run  into  the  mold 
the  top  surface  of  the  neck  will  be  covered  with  superheated 
Thermit  steel  to  a  depth  of  about  1  in.,  and  the  slag  from 


WELDING   NEW  NECKS  ON   LARGE  STEEL  PINIONS     379 

the  Thermit  reaction  will  flow  from  the  crucible  and  run  out 
of  the  V-shaped  notch  in  the  side  of  the  runner,  thereby 
preventing  any  slag  from  entering  the  mold. 

The  overflow  runner  should  have  sufficient  pitch  so  that 
the  liquid  steel  will  flow  to  the  ingot  mold  readily  without 
spattering.  Firebricks  should  be  laid  on  top  of  the  ingot  mold 
in  order  to  prevent  steel  from  spattering  at  that  point. 

When  the  mold  is  completed  start  the  preheating  of  the 
body  of  the  pinion.  If  gasoline  or  kerosene  is  used  three 
double  or  five  single  preheaters  will  be  required  and  another 
one  should  be  kept  filled  and  ready  to  be  cut  in  when  any 
one  of  the  others  has  become  empty.  This  will  prevent  loss 
of  heat  while  a  preheater  tank  is  being  refilled. 

As  the  body  of  the  pinion  approaches  a  red  heat  start 
.the  preheating  cf  the  top  of  the  neck  as  shown  in  Fig.  32-B. 
Heat  this  surface  to  a  good  red  heat,  timing  the  operation 
so  as  to  have  both  neck  and  body  of  pinion  red  hot  at  the 
time  the  openhearth  steel  is  tapped  out  of  the  furnace. 

While  the  preheating  of  the  neck  is  progressing  set  the 
automatic  crucible,  size  7,  charging  it  in  accordance  with 
previous  directions,  so  that  it  will  be  ready  when  needed. 

Amount  of  Thermit  Required. — In  calculating  the  amount 
of  Thermit  required  for  this  type  of  repair  allow  75  Ib.  of 
railroad  Thermit  for  each  square  foot  of  surface  it  is  desired 
to  melt  down. 

Be  sure  that  the  cope  has  been  baked  while  the  preheating 
of  the  neck  is  going  on  (either  in  an  oven  or  as  shown  in 
Fig.  32-H)  and  is  located  conveniently  so  that  it  can  be  brought 
up  with  the  crane  at  the  proper  time.  After  the  furnace  is 
tapped  raise  the  ladle  of  steel  and  try  the  stopper  by  making 
a  couple  of  pours  to  be  sure  that  the  stopper  ivorks  properly 
and  will  shut  off  tight. 

Move  the  ladle  to  a  point  near  the  mold  so  that  no  time 
may  be  lost  between  pouring  the  Thermit  steel  and  washing 
through  the  steel  from  the  ladle.  Remove  the  preheaters  to  a 
safe,  distance. 

Ignite  the  charge  of  Thermit  in  the  crucible,  and  when  the 
reaction  is  over  (usually  35  to  50  sec.)  tap  the  Thermit  steel 
into  the  mold,  as  shown  in  Fig.  40.  When  all  the  steel  from 
the  crucible  has  flowed  into  the  mold  the  slag  will  commence 


380 


GAS  TORCH  AND  THERMIT  WELDING 


to  run  over  the  V-shaped  notch  in  the  pouring  runner.  Move 
the  crucible  out  of  the  way  and  plug  the  pouring  gate  with 
a  sand  core  provided  for  this  purpose,  banking  up  securely 
behind  it  to  prevent  leakage. 

Lower  the  ladle  of  openhearth  steel,  shown  at  the  left, 
to  a  point  close  to  the  top  of  the  mold  and  tap  the  steel  into 


FIG.   40. — Welding  a   Boll    Neck.     Thermit    Steel   Tapped    into    Mold  and 
Ladle  of  Steel  at  Left  Beady  for  Final  Operation. 

the  mold,  running  through  about  5000  Ib.  into  the  ingot  mold 
which  has  been  set  for  the  purpose,  as  shown. 

Plug  the  runner  gate  with  a  core  constructed  as  shown  in 
Fig.  32-J  and  bank  up  well  behind  it  so  that  there  will  be  no 
danger  of  a  runout.  Be  careful  in  plugging  this  gate  on  account 
of  its  size.  After  the  plugging  is  completed  and  banked  up, 
the  sand  should  be  weighted  down  as  an  extra  precaution  to 
prevent  accident. 


WELDING   NEW   NECKS 'ON   LARGE  STEEL  PINIONS     381 

After  the  overflow  has  been  securely  plugged  fill  up  the 
mold  with  steel  from  the  ladle  and  cover  it  well  with  dry 
sand  or  charcoal  to  keep  the  metal  hot. 


FIG.  41. — Eoll  Neck  Welded  to  Large  Steel  Roll  with  Pods  Cast  in. 

Treatment  When  a  Cope  is  Used. — If  a  cope  is  used  clean 
off  the  surface  of  the  top. of  the  mold  and  set  on  the  cope, 
clamping  it  securely,  and  then  fill  the  cope  to  the  height  desired 


TIG.  42. — New  Neck  Welded  to  Large  Steel  Pinion.     In  this  Case  the  Pods 
Were  Milled  Afterward. 

with  steel  and  again  cover  over  with  dry  sand  or  powdered 
charcoal. 

If  the  body  of  the  roll  or  pinion  has  cooled  to  any  extent 
it  would  be   desirable  to  again  preheat  it.     After  the  body 


382 


GAS  TORCH  AND   THERMIT  WELDING 


of  the  pinion  is  sufficiently  preheated  cover  the  pit  to  make 
it  as  nearly  airtight  as  possible,  so  as  to  cause-  the  roll  or 
pinion  to  cool  slowly.  By  doing  this  further  annealing  is 
unnecessary. 


FIG.  43. — Worn  Pods  Built  Up  with  Thermit  Steel.  The  Eepair  Consisted 
of  Four  Welds  Made  Simultaneously,  using  Two  Pouring  Gates  and 
Two  Crucibles. 


FIG.  44. — Building  Up  Worn  Pods  by  Means  of  Three  Thermit  Welds. 
Pouring  Gates  Were  Connected  at  Top  and  Bottom  to  Insure  Equal 
Distribution  of  Metal. 

After  the  pinion  is  sufficiently  cool  (usually  about  48  hours 
or  more)  remove  from  the  mold  and  machine  to  size. 

In  some  steel  plants  it  is  considered  preferable  not  to  use 


WELDING   NEW  NECKS  ON   LARGE  STEEL  PINIONS     383 

a  cope  but  to  build  the  mold  all  in  one  piece  to  the  height 
of  the  new  neck.  This  method  simplifies  the  making  of  the 
mold  and  the  pouring  of  the  weld,  but  sometimes  complicates 
the  operation  for  the  following  reasons: 

When  riser  patterns  are  withdrawn  it  is  a  little  more  diffi- 
cult to  remove  loose  sand  from  the  mold. 

In  preheating  it  is  not  so  easy  for  the  operator  to  see  what 
he  is  doing. 

There  are  times  when  these  necks  will  be  as  much  as  5  ft. 
high,  which  makes  it  a  little  unhandy  to  work  around  the  mold. 

There  are  numerous  arguments  on  both  sides  of  the  ques- 
tion, but  we  feel  that  either  method  will  give  good  results. 
For  short  necks,  however,  a  cope  can  probably  be  dispensed 
with  without  introducing  any  difficulty. 

Two  welding  jobs  just  as  they  came  from  the  molds  are 
shown  in  Figs.  41  and  42.  The  first  is  a  neck  welded  onto 
a  large  steel  roll  with  the  pods  cast  in.  The  second  one  shows 
a  new  neck  welded  to  a  large  steel  pinion.  In  this  last  case 
the  pods  were  milled  out  afterward. 

Two  other  wielding  jobs  are  shown  in  Figs.  43  and  44.  These 
both  illustrate  the  repair  or  replacing  of  worn  pods  on  heavy 
steel  mill  pinions. 

Alternative  Method. — While  the  preceding  directions  cover 
the  welding  of  pinions  under  what  might  be  considered  ideal 
conditions  it  is  not  always  possible  to  do  the  work  in  this 
way,  and  where  such  is  the  case  we  would  recommend  that 
the  following  directions  be  followed,  as  they  represent  a 
simpler  method,  yet  one  which  has  always  resulted  in  satis- 
factory repairs. 

Patterns,  mold  box,  runners,  etc.,  should  be  constructed 
in  accordance  with  directions  given  for  the  previous  method. 

In  these  repairs  great  care  should  be  exercised  in  supporting 
the  pinion  so  that  there  is  no  danger  of  its  settling  under  the 
added  weight  of  the  mold  and  the  steel  which  is  poured  into 
it.  If  it  is  not  desired  to  go  to  the  expense  of  constructing 
a  special  pit  as  outlined  in  the  previous  method  a  satisfactory 
and  economical  way  is  to  dig  a  hole  in  the  ground  about  8  ft. 
in  diameter  and  of  sufficient  depth  to  receive  at  least  f  of  the 
entire  length  of  the  pinion.  Cover  the  bottom  of  the  hole  by 
laying  a  double  flooring  of  2-in.  planking,  being  careful  that 


384 


GAS   TORCH  AND   THERMIT   WELDING 


the  planks  in  one  layer  run  in  opposite  directions  to  those  of 
the  other  layer. 

On  top  of  this  place  a  steel  plate  in  order  to  distribute  the 
weight  of  the  pinion  over  the  entire  floor  area.  Such  a  founda- 
tion has  always  proved  adequate  and  is  not  expensive. 


CRUCIBLE 


• 

^•iT4^-=-'-u-?^r-^^itra . 
Foundation  to  suit  condition  of  ' 
-^  ground  etc.  In  all  cases  see  that 
mold  is  supported  on  roll  independent 
of  floor.  Size  and  number  ofmold 
boxes  to  suit  roll. 


afher 

is  washed  ocrf 


\i  45. — Alternate  Method  of  Supporting  Roll  or  Pinion  to  Be  Repaired. 


Set  the  pinion  in  the  hole  so  that  the  surface  to  be  welded 
ii  level  and  fill  in  all  around  the  pinion  with  dirt,  ramming 
hard  to  hold  the  pinion  permanently  in  position. 

Dig  a  second  hole  alongside  of  the  buried  pinion  to  receive 
the  ingot  mold.  This  should  be  at  such  a  distance  from  the 
pinion  that  a  suitable  runner  for  the  overflow  steel  can  easily 


WELDING  NEW  NECKS  ON  LARGE  STEEL  PINIONS     385 

be  placed.     The  top  of  the  ingot  mold  should,  of  course,  be 
lower  than  the  top  of  the  roll  or  pinion  neck. 

If  the  neck  is  broken  off  close  to  the  body  of  the  pinion 
it  is  absolutely  necessary  to  provide  arrangements  for  pre- 
heating the  body  protruding  above  the  ground  in  order  to 
avoid  shrinkage  strains.  A  simple  way  to  do  this  is  to  build 
up  a  brick  furnace  and  heat  in  accordance  with  directions 
relating  to  casting  of  teeth  in  large  pinions,  and  more  of  the 
pinion  body  should  protrude  above  the  ground  than  shown  in 
Fig.  45.  If,  however,  there  is  one  foot  or  more  of  neck  pro- 
truding from  the  body  of  the  pinion,  it  is  not  absolutely  neces- 
sary to  preheat  the  rest  of  the  pinion. 

THE  MOLD  BOX 

The  mold  box  should  be  constructed  with  heavy  steel  flasks 
or  a  substitute  made  of  at  least  J-in.  plate  and  should  be 
supported  entirely  on  the  roll  and  independent  of  the  ground. 


FIG.  46. — Finished   Weld  on  Anchor  Davit  of   U.   S.   S.   ' '  Olympia. ' ' 

With  the  mold  box  adjusted  in  place  ram  up  with  good 
molding  material  in  accordance  with  the  previous  directions 
and  then  draw  out  the  various  wooden  patterns.  Nails  or 
chaplets  should  be  driven  into  the  sand  so  as  to  hold  it  firmly 
in  place.  It  is  advisable  to  coat  the  mold  with  a  good  steel 
wash.  When  the  mold  is  completed  the  preheating  of  the 
body  of  the  pinion  should  be  started  if  the  repair  is  of  such 
a  nature  as  to  require  this  preheating.  If  this  heating  is  not 


386 


GAS  TORCH   AND   THERMIT   WELDING 


necessary  start  preheating  on  top  of  the  neck  as  shown  in 
Fig.  32-B.  If  the  body  of  the  pinion  is  heated  the  heating 
of  the  neck  should  not  be  started  until  the  pinion  approaches 
a  red  heat. 


FIG.  47. — Anchor  of  the  Morgan  Yacht  " Corsair" 
Eepaired  with  Thermit. 


FIG.  48. — Weld  on  Wheel  Shaft  Of  Steamer  "Nashville"  on 
the  Cumberland  River,  Made  in  1912. 

Heat  the  surface  on  top  of  the  neck  to  a  good  red  heat, 
timing  the  operation  so  that  it  will  be  red  hot  at  the  time 
the  openhearth  steel  is  tapped  out. 


WELDING  NEW  NECKS  ON  LARGE  STEEL  PINIONS     387 


<  49. — y?eld  on  10-in.  Wheel  Shaft  of  Steamer  ' '  Osceola, ' ' 
Made  at  Jacksonville,  Fla.,  in  1915. 


FIG.  50.— Weld  on  Sternpost  of  Tug  No.  32,  Made  September,  1911. 


388. 


GAS  TORCH   AND   THERMIT   WELDING 


While  the  preheating  of  the  neck  is  progressing  set  an 
automatic  crucible,  size  7,  as  shown  in  Fig.  45,  and  charge 
it  so  that  it  will  be  ready  when  needed.  If  possible  it  is  best 
to  support  the  crucible  with  a  crane  so  that  it  can  be  quickly 
removed  after  it  has  been  tapped.  The  procedure  is  then  the 
same  as  described  for  the  previously  given  method.  After 
cooling,  strip  the  mold  and  machine  the  parts  to  proper  size. 

It  is  sometimes  desirable  where  the  body  of  the  pinion 
has  been  preheated  to  continue  this  heating  after  the  weld 


FiG.  51. — Sternpost  Weld  on  the  ' '  William  Henry  Mack, ' '  July,  1912. 

is  completed.  This  can  easily  be  done  by  again  igniting  the 
burners  directed  into  the  brick  furnace.  After  the  body  is 
sufficiently  preheated  remove  the  burners  and  fill  in  between 
the  bricks  and  the  pinion  with  dry  sand  so  as  to  cause  slow 
cooling.  By  doing  this  further  annealing  is  unnecessary.  As 
previously  mentioned,  a  cope  may  or  may  not  be  desirable,  and 
this  is  left  to  the  judgment  of  the  operator. 

Marine  Work. — The  general  principles  to  be  followed  in 
making  marine  repairs  are  the  same  as  for  any  other  repairs 
of  a  similar  size  and  nature,  so  no  detailed  description  need 


WELDING  NEW  NECKS  ON   LARGE  STEEL  PINIONS     389 

be  given.  However,  it  will  be  of  interest  to  know  the  exact 
nature  of  some  of  the  more  common  repairs  made  on  anchors, 
wheel  shafts,  sternposts  or  the  like,  so  a  few  views  of  some 
of  the  actual  repairs  are  shown.  A  big  point  in  favor  of  the 
Thermit  process  in  cases  like  the  ones  given  is  the  short  time 
necessary  for  the  ship  to  be  laid  up.  In  many  cases  little 
or  no  dismantling  is  necessary.  In  a  number  of  stern  shoe 
welds  on  lake  steamers  the  sizes  of  the  parts  at  the  break  have 


FIG.  52. — Another    Sternpost   Weld.      S.    S.    ''Corunna"    of   the   Canadian 
Lake  Transportation  Co.,  Made  in  1907. 

been  from  11X16  in.  to  10X20  in.  or  more,  and  the  average 
time  required  has  been  about  36  hours  complete.  On  a  large 
number  of  ocean-going  vessels  the  welds  made  have  been  on 
sections  of  larger  dimensions  than  those  quoted. 

In  Fig.  46  is  shown  a  weld  on  the  anchor  davit  of  the  fam- 
ous U.  S.  S.  "Olympia."  Fig.  47  shows  a  repair  on  the  anchor 
of  the  Morgan  yacht  "Corsair."  Fig.  48  is  a  repai-r  on  the 
wheel  shaft  of  the  "Nashville,"  a  Cumberland  River  steam- 
boat, made  in  1912.  Fig.  49  shows  a  repair  on  the  wheel  shaft 


390  GAS  TORCH  AND  THERMIT  WELDING 

of  the  river  steamer  "Osceola, "  welded  at  Jacksonville,  Fla., 
in  1915.  Fig.  50  shows  a  sternpost  weld  on  a  tug,  made  in 
1911.  Another  sternpost  weld  is  shown  in  Fig.  51.  Still 
another  very  similar  weld  is  shown  in  Fig.  52.  These  are 
sufficient  to  give  the  reader  a  good  idea  of  the  application 
of  the  process  to  this  class  of  work. 


CHAPTER  VI 
RAIL  WELDING  FOR  ELECTRIC  SYSTEMS 

Probably  no  problem  in  recent  years  has  received  more 
consideration  at  the  hand  of  traction  companies  than  the 
subject  of  track  construction  and  maintenance.  Progress  along 
this  line  has  been  continuous  and  expense  has  not  been  spared 
to  obtain  the  best  roadbed  possible;  heavier  rails  are  being 
used  and  particular  attention  is  paid  to  the  foundation,  ties 
and  drainage;  everything  is  of  the  best  material  and  work- 
manship until  it  comes  to  joining  the  rails  together,  and  here 
there  usually  develops  the  weak  point  of  the  entire  system. 
This  refers  to  the  mechanical  joints  in  common  use.  No  matter 
how  much  care  is  taken  in  applying  splice  bars  mechanical 
discrepancies  and  disadvantages  cannot  be  overcome;  the  rail 
sections  are  seldom  uniform  and  the  American  Society  for 
Testing  Materials  has  adopted  specifications  which  limits  a 
maximum  difference  in  height  to  3/64  inch.  Variable  height 
in  new  rails  is  often  unavoidable,  as  joint  plates  fitting  one 
rail  perfectly  may  not  fit  its  neighbor. 

There  are  many  reasons  why  the  mechanical  joint  fails  to 
fulfill  its  function,  which  are  not  necessary  to  enumerate  here. 
On  the  other  hand  the  advantages  of  a  welded  rail  joint,  where 
circumstances  will  permit,  are  plain.  While  there  are  several 
systems  by  which  rail  joints  may  be  welded,  at  the  present 
time  the  Thermit  method  is  the  only  one  that  absolutely 
eliminates  the  joint.  It  also  has  advantages  in  the  modified 
joint-welding  work.  These  advantages  will  become  clear  as 
our  description  of  the  actual  processes  develops.  Briefly,  the 
weld  is  accomplished  by  pouring  the  superheated  steel  obtained 
from  the  Thermit  reaction  into  a  mold  surrounding  the  rail 
ends  at  the  joint.  This  fuses  with  the  base  and  web  of  the 
rail  as  well  as  with  the  lip  and  one  side  of  the  head.  An  insert 
cut  from  a  rolled  section  of  similar  analysis  to  that  of  the 

391 


392  GAS  TORCH  AND  THERMIT  WELDING 

rail  itself  is  placed  between  the  heads  at  the  running  face, 
and  the  lower  part  of  this  insert  is  melted  into  the  Thermit 
steel.  The  mold  is  so  constructed,  however,  that  the  head 
of  the  rail  and  the  top  part  of  the  insert  are  not  melted  but 
are  merely  heated  to  a  welding  temperature,  so  that  when  the 
Thermit  metal  begins  to  cool  and  contract,  thus  drawing  the  rail 
ends  together  with  tremendous  force,  the  squeezing  action 
oil  each  side  of  the  insert  thoroughly  butt  welds  it  into  the 
head.  When  this  has  been  accomplished  the  running  face  is 
ground  to  a  true  surface  and  the  surplus  metal  ground  out 
of  the  groove.  The  weld  obtained  in  this  way  is  so  perfect 
that  it  is  practically  impossible  to  detect  its  location  after 
tlie  rails  have  been  paved  in. 

In  practice  the  welding  is  best  done  after  the  ties  have  been 
concreted.  If  the  welding  is  done  before  the  concreting  it  is 
somewhat  difficult  to  keep  the  rails  in  perfect  alignment  and 
to  proper  surface  after  the  temporary  splice  bars  have  been 
moved.  The  rails  are  spaced  J  in.  apart  and  must  be  thoroughly 
cleaned  for  a  distance  of  4  in.  from  each  end.  This  can  be 
accomplished  by  using  a  small  steel-wire  brush.  The  ends  of 
the  rail  heads  must  next  be  cleaned  and  where  necessary  filed 
smooth  so  that  when  the  insert  is  fitted  the  maximum  amount 
of  contact  surface  will  be  obtained.  In  other  words  the  insert 
must  be  made  to  fit  accurately.  Following  this  the  rails  are 
brought  to  proper  surface  and  alignment,  care  being  taken 
to  keep  the  rail  ends  a  trifle  high,  so  that  when  a  straightedge 
about  30  in.  long  is  centered  over  a  joint  there  will  be  a  space 
of  about  1/32  in.  between  the  ends  of  the  straightedge  and 
the  surface  of  the  rail  directly  under  it.  This  slight  raising 
of  the  rail  ends  has  been  found  necessary  in  practice,  as  it 
assures  proper  alignment  and  surface  after  grinding. 

PLACING  THE  INSERT 

The  joint  is  now  ready  for  the  placing  of  the  insert,  as 
shown  in  Fig.  53.  Various  thicknesses  of  inserts  must  be 
kept  on  hand  to  fit  the  variation  in  gap  brought  about  by 
temperature  changes  and  other  causes.  With  the  inserts  in 
position  two  part  sand  molds  are  applied,  as  shown  in  Fig.  54. 
these  are  rammed  in  advance  on  a  foundry  squeezing  machine 
over  a  wooden  pattern,  the  dividing  line  of  the  molds  being 


RAIL  WELDING  FOR  ELECTRIC  SYSTEMS  393 


FIG.  53. — Adjusting  Insert  Between  Kails. 


FIG.  54. — Adjusting  Two-Part  Mold  to  Rails. 


394 


GAS  TORCH  AND  THERMIT  WELDING 


in  the  center  of  the  web.     A  squeezing  machine  being  used 
for  this  purpose  is  shown  in  Figs.  55  and  56. 

The  pattern  is  so  constructed  as  to  form  an  opening  around 
the  rail  ends  in  the  shape  of  a  collar  into  which  the  Thermit 
steel  is  poured.  This  collar  is  usually  about  3  in.  wide  and 


FIG.  55. — Ramming  Molds  on  a  Squeezing  Machine.     Wooden  Patterns  and 
Sheet-Iron  Mold  Box  in  Foreground. 

varies  from  |  in.  to  f  in.  in  thickness,  depending  on  the  rail 
section  to  be  welded.  Pouring  gates  and  risers  are  also  pro- 
vided for  in  the  mold  in  a  similar  manner  to  those  already 
described. 

Kecent  improvements  in  the  construction  of  the  molds  used 


RAIL  WELDING  FOR  ELECTRIC  SYSTEMS 


395 


have  been  perfected  to  guard  against  runouts.  A  bead  pro- 
trudes around  certain  parts,  so  that  when  the  two  halves  are 
clamped  together  it  is  compressed  between  them  and  forms 
a  safeguard  against  the  liquid  steel  running  out. 

Before  clamping  the  molds  to  the  rails  two  cords  of  asbestos 


FIG.  56. — Cutting  Heating  Gate  in  Mold.     Finished  Mold  and  Wooden 
Pattern  Shown  in  Foreground. 

soaked  in  molasses  are  applied  around  the  contour  of  the  rail, 
one  on  each  side  of  the  joint,  as  shown  in  Fig.  57,  and  placed 
in  such  a  position  that  they  will  come  just  inside  the  outer 
edge  of  the  mold  box.  The  molasses  is  sufficiently  sticky  to 
make  these  cords  adhere  tightly  to  the  rail  and  form  a  very 


396  GAS  TORCH  AND  THERMIT  WELDING 

efficient  luting  all  around  the  outside  edge  between  the  mold 
and  the  rail.  As  an  additional  precaution  a  small  amount  of 
fireclay  is  blown  into  the  mold  through  the  pouring  gate  by 


FIG.  57. — Applying    Asbestos    and    Molasses    Strips   to    Kails    Previous    to 

Placing  Mold. 


FIG.  58. — Final  Luting  Process,  Blowing  Powdered  Fire  Clay  into  the  Mold. 

means  of  compressed  air,  as  shown  in  Fig.  58,  while  the  other 
openings  are  closed  temporarily  by  inserting  wooden  plugs. 
Should  there  be  any  opening  around  the  edges  of  the  mold 


RAIL  WELDING  FOR  ELECTRIC   SYSTEMS  397 

the  fire  clay  escaping  through  that  opening  will  be  caught 
by  the  molasses  011  the  asbestos  cords  and  the  opening  auto- 
matically sealed.  When  the  air-pressure  gage  indicates  that 
the  mold  is  tight  the  wooden  plugs  are  removed  and  all  surplus 
fire  clay  blown  out  through  a  small  blowout  gate  provided 
in  the  lower  part  of  the  mold. 

Preheating. — The  rails  are  now  ready  for  preheating,  and 
must  be  brought  to  a  bright-red  heat.  For  this  purpose  a 
special  portable  heater  is  used. 

The  opening  in  the  mold  through  which  the  rails  are  heated 


FIG.  59. — Mold  and  Crucible  Clamped   in  Position  Ready  for   Preheating. 
Box  Containing  Additions  Set  in  Riser  of  Mold. 

is  situated  about  two-thirds  from  the  top,  so  that  the  flame 
strikes  the  lower  portion  of  the  web  of  the  rail  and  has  the 
effect  of  heating  the  entire  rail  section  uniformly.  This  pre- 
heating also  accomplishes  two  other  objects,  as  it  bakes  the 
mold  and  at  the  same  time  heats  up  a  can  of  additions  which 
are  added  to  the  Thermit  in  the  crucible  to  improve  the  quality 
of  the  steel  produced.  This  can  of  additions  is  placed  on 
top  of  the  mold  in  a  special  receptacle  provided  for  the  purpose 
in  the  riser  opening,  as  sliown  in  Fig.  59.  As  soon  as  the 
rails  are  red  hot,  the  mold  thoroughly  dried,  and  the  can  of 


398 


GAS  TORCH  AND  THERMIT  WELDING 


additions  heated  to  the  proper  temperature,  the  burner  is  with- 
drawn and  the  heating  gate  plugged  with  a  sand  core.  The 
burner  is  then  directed  down  the  pouring  gate  in  order  to 
restore  any  heat  that  may  have  been  lost  during  the  plugging 
operation. 

The  mold  is  now  ready  for  pouring,  and  the  crucible  is 
placed  in  position,  the  reaction  started  and  the  melt  tapped, 
just  as  described  for  other  work  of  this  character. 

The  steel  enters  the  mold  on  the  lip  side  of  the  rail  and 
thoroughly  melts  and  amalgamates  with  the  lip  as  well  as  with 


POURING  GATE 


RISER 


STEEL  INSERT 
OF  SAME  MATERIAL    |>       WELDED  IN 
AS  RAIL 


POURING  GATE 


Top  View  of  Rail  Joint 
before  Grinding 


Section  through  Rail  Joint 
after  Pouring 

FIG.  60.  —  Sectional  View  of  Eail  Weld. 


the  web,  base  and  one  side  of  the  head.  No  Thermit  steel 
is  allowed  to  touch  the  running  surface  of  the  rail,  as  the 
steel  insert  closes  up  the  space  between  the  rail  ends  except 
for  a  small  opening  of  about  £  in.  from  the  outside  of  the 
head.  The  under  part  of  the  insert  is  thoroughly  fused  with 
the  liquid  steel  and  becomes  a  part  of  the  fusion  weld,  as  shown 
in  Fig.  60. 

As  explained  previously,  when  the  metal  in  the  weld  begins 
to  cool  it  produces  sufficient  pressure  on  each  side  of  the  insert, 
due  to  contraction,  to  thoroughly  butt  weld  it  in  position  so 
that  at  the  end  of  the  operation  the  entire  rail  is  welded  into 


RAIL  WELDING  FOR  ELECTRIC  SYSTEMS 


399 


one  homogeneous  mass.  A  finished  weld  is  shown  in  Fig.  61 
and  in  Fig.  62  is  shown  a  number  of  operations  going  on 
at  once. 

One  of  the  principal  advantages  of  this  type  of  weld  is 


FIG.  61. — Finished  Thermit  Fully  Welded  Insert  Joint. 

that  it  depends  on  a  predetermined  chemical  reaction  which 
is  always  uniform.  The  success  of  the  reaction  is  assured  by 
the  fact  that  every  Thermit-welding  portion  is  weighed  out 


FlG.  62. — Preheating  Bails,  Drying  Molds  and  Heating  Thermit  Additions, 
All  in  One  Operation,  Four  Joints  Being  Heated  at  Once. 

separately  for  each  rail  section  to  be  welded  and  in  just  the 
proper  quantity  to  obtain  a  perfect  weld  on  that  section. 

The  placing  of  the  additions  in  a  sheet-iron  container  is  a 
fairly  recent  improvement  and  has  resulted  in  not  only  obtain- 
ing a  higher  grade  of  steel  in  the  weld  than  was  possible 


400  GAS   TORCH  AND   THERMIT  WELDING 

formerly  but  also  permits  of  obtaining;  a  greater  quantity  of 
steel  from  the  Thermit  used.  This  in  turn  permits  a  weld  to 
be  made  with  less  Thermit  than  formerly  and  has  considerably 
reduced  the  expense  of  the  welded  joints. 

THE  USE  OF  ADDITIONS 

The  scheme  of  employing  the  additions  as  outlined  is  to 
use  plain  Thermit,  ami!  instead  of  mixing  the  additions  of 
manganese,  nickel  and  other  materials  for  improving  the 
quality  of  the  Thermit  steel  throughout  the  Thermit  itself  these 
additions  are  now  put  up  in  the  sheet-iron  container  which 
is  placed  on  top  of  the  mold  during  the  preheating  and  is  heated 
red  hot  by  the  waste  gases.  It  is  then  placed  in  the  center 
of  the  crucible  and  is  melted  down  by  the  heat  of  the  Thermit 
reaction. 

This  method  enables  the  production  of  more  steel  from  a 
given  amount  of  Thermit 'without  any  sacrifice  of  heat,  with 
the  result  that  the  cost  of  the  welding  portion  of  Thermit  is 
considerably  reduced. 

After  the  weld  has  been  poured  ike,  mold  should  be  left 
undisturbed  for  a  few  hours;  in  fact,  the  longer  it  is  allowed 
to  co01  the  better,  as  the  metal  in  the  weld  has  time  to  become 
properly  annealed.  The  mold  boxes  can  then  be  removed, 
the  metal  left  in  ./.the  risers  and  pouring  gates  cut  off  by 
nicking  with  a  hammer  and; chisel  and  knocking  off.  All  sand, 
etc.,  is  cleaned  from  the  rail  in  the  vicinity  of  the  mold  and 
the  joint  is  ready  for  grinding. 

The  Grinding  Machine.— As  the  steel  insert  is  left  a  trifle 
higher  than  the  rail  section  this  excess  metal  must  be  ground 
off  together  with  the  excess  metal  left  in  the  groove  "and  on 
the  outside  of  the  head  where  the  riser  is  removed. 

This  grinding  can  best  be  accomplished  by  means  of  the 
machine  shown  in  Fig.  63.  It  possesses  the  advantage  that 
the  weight  is  concentrated  over  the  grinding  wheels  so  that 
a  deeper  cut  can  be  taken.  It  also  has  attachments  permitting 
of  grinding  in  the  groove  of  the  rail  and  on  the  gage.  If 
only  a  very  few  joints  are  being  welded,  however,  the  grinding 
can  be  very  satisfactorily  accomplished  with  a  flexible-shaft 
grinding  machine.  In  fact  one  of  the  great  advantages  of 


RAIL  WELDING   FOR  ELECTRIC  SYSTEMS 


401 


the  Thermit  process  of  rail  welding  is  that  a  few  joints  can 
be  welded  almost  as  economically  as  a  large  number,  and  trac- 
tion companies  can  do  the  work  themselves  wherever  they 
please,  and  when  the  work  is  properly  organized  a  gang  of 
nine  men  can  weld  from  35  to  40  joints  in  a  nine-hour  day. 

The  simple  and  portable  character  of  the  welding  outfit, 
including  the  grinding  machine,  is  a  strong  point  of  merit, 
as  one  service  car  will  carry  all  the  equipment  or  it  can  be 
hauled  on  its  own  wheels. 


FIG.  63. — Rail-Grinding  Machine  Derailed  Under  Its  Own  Power. 

The  rail-grinding  machine  referred  to  was  originally  de- 
signed by  the  Thermit  company  for  grinding  Thermit-welded 
rail  joints,  but  has  proved  very  efficient  for  grinding  out 
corrugations,  pounded  joints,  and  in  fact  anything  that  is 
required  for  a  rail-grinding  machine  on  an  electric-railway 
system.  An  important  feature  is  the  derailing  device  which 
permits  the  removal  of  the  machine  from  the  path  of  traffic 
very  quickly.  The  concentration  of  the  weight  over  the  grind- 
ing wheels  has  already  been  mentioned.  By  this  arrangement 
deep  or  light  cuts  may  be  taken  without  danger  of  the  grind- 
ing wheels  chattering.  The  truck  frame  carries  two  axles. 


402  GAS  TORCH  AND  THERMIT  WELDING 

One  axle  is  fitted  with  ordinary  22-in.  car  wheels  and  the 
other  has  eccentrically  mounted  13-in.  wheels.  By  means  of 
sliding  adjustments  the  wheels  may  be  spaced  on  their  axles 
to  fit  road  gages  of  from  4  ft.  8-J  in.  to  5  ft.  2J  in.  The  grind- 
ing-wheel  brackets  have  both  vertical  and  horizontal  movement 
to  allow  for  adjustment  to  the  work.  The  bracket  also  may 
be  rotated  so  that  the  face  of  the  grinding  wheel  may  be 
adjusted  to  the  surface  to  be  ground.  By  a  special  arrange- 
ment of  the  motors  used  the  machine  can  be  driven  forward 
at  a  rate  of  2  or  4  ft.  per  minute  and  6  to  12  ft.  per  minute  on 
the  return.  A  reversing  switch  permits  speeds  to  be  used 
in  either  direction. 

Where  it  is  desired  to  grind  out  a  depression  a  special 
arrangement  is  used  by  which  an  accurate  curve  is  obtained. 
The  grinding  wheels  run  about  1833  r.p.m.,  which  corresponds 
to  a  peripheral  speed  of  6719  ft.  per  minute  on  a  new  14-in. 
wheel.  The  grinding-wheel  motors  are  rated  at  3J  hp.  and  the 
propelling  motor  at  If  hp.,  and  they  are  designed  to  operate 
on  500  to  550  volts.  The  derailing  device  operates  by  power 
and  is  quickly  brought  into  use.  The  complete  machine  weighs 
about  6000  pounds. 


CHAPTER  VII 
WELDING  COMPROMISE  RAIL  JOINTS 

There  is  very  often  a  demand  for  a  compromise  joint  to 
be  supplied  quickly  when  some  bolted  or  cast-welded  joint 
has  failed.  An  inexpensive  shop-welding  outfit  enables  traction 
companies  to  weld  their  own  compromise  joints  in  a  few 
hours,  and  these  will  give  the  same  results  in  service  as  a 
regular  Thermit  rail  weld. 

When  a  large  number  of  compromise  joints  are  to  be  made 
on  the  same  rail  section  it  is  advisable  to  have  patterns  and 
mold  boxes  made  especially  for  the  purpose.  Where  only 
two  or  three  are  to  be  welded,  however,  the  work  can  be  done 
by  the  "wax  method,"  which  is  the  method  used  in  all  general 
repair  work.  To  assist  in  the  aligning  and  surfacing  of  the 
rails  when  two  short  lengths  are  to  be  welded  together  it  is 
advisable  to  provide  a  suitable  bed  to  which  the  rails  can 
be  bolted.  Two  stringers  running  about  10  in.X6  in.XlO  ft. 
long,  on  which  four  wooden  or  steel  ties  can  be  bolted,  answer 
this  purpose  very  well.  The  two  center  ties  should  be  spaced 
about  18  in.  in  the  clear  and  the  second  tie  spaced  to  take 
care  of  the  shortest  length  of  rail  to  be  welded.  It  is  best  to 
imbed  the  surfacing  bed  in  the  ground  up  to  the  top  of  the 
stringer.  To  hold  the  rails  to  the  ties  long  bolts  can  be  used 
in  place  of  track  spikes.  These  bolts  should  be  allowed  to 
project  through  the  face  of  the  tie  a  sufficient  amount  to  take 
the  smaller  of  the  two  rails.  Allowance  must  also  be  made 
for  a  U-clamp,  or  bridge  clip,  one  end  of  which  will  bear  on 
the  base  of  the  rail  and  the  other  on  the  tie,  or  in  the  case 
of  a  small  rail,  will  rest  on  a  spacing  block. 

To  bring  the  smaller  rail  up  to  the  surface  of  the  high  rail 
a  filling  block  is  placed  under  the  base,  and  to  obtain  accurate 
surfacing,  shims  or  old  hack-saw  blades  may  be  used  in  addi- 
tion. With  the  rails  spaced  J  in.  apart  and  accurately  adjusted, 

403 


404  GAS  TORCH  AND  THERMIT  WELDING 

the  U-clamps  are  bolted  down  tight  and  the  insert  fitted  as 
described  for  making  ordinary  rail  welds.  If  patterns  and 
mold  boxes  have  been  provided  in  advance  the  work  proceeds 
in  the  same  way  as  for  ordinary  rail  welding,  but  if  the  wax 
method  is  to  be  used  about  3  Ib.  of  wax  should  be  broken 
into  small  pieces,  placed  in  a  pan  and  heated  until  entirely 
melted.  The  wax  is  then  allowed  to  cool  until  it  becomes 
plastic.  It  may  then  be  shaped  by  hand  around  the  rail  ends 
in  the  form  of  a  collar. 

USING  A  RAIL  SECTION  FOR  A  PATTERN 

In  cases  where  five  or  six  compromise  joints  are  to  be 
welded  between  the  same  rail  sections  considerable  time  and 
trouble  can  be  saved  by  using  a  short  length  of  each  rail 
section  as  a  pattern.  These  should  be  about  8  in.  long,  butted 
together  and  fastened  by  tacking  with  the  oxy-acetylene-weld- 
ing  process  so  that  they  will  be  held  together  securely.  Mold 
boxes  of  sheet  iron  in  two  halves  can  be  cut  to  fit  with  the 
oxy-acetylene  cutting  flame  so  that  they  will  fit  the  sections 
to  approximately  Vie  in-  all  around.  Each  half  of  the  mold 
box  will  then  have  a  different  section  cut  in  each  side.  A 
wax  collar  is  formed  around  the  joint  of  the  two  pieces  of 
rail  in  the  regular  way  as  described  above  and  the  one-half 
of  the  mold  box  is  laid  on  the  ground  back  down,  placing  the 
pattern  made  by  tacking  the  two  rail  sections  together  on  this 
half  of  the  mold  box.  Then  thin  pieces  of  sheet  iron  are  laid 
on  top  of  this  half  to  obtain  a  parting  when  the  other  half 
of  the  mold  box  is  placed  on  top.  The  other  half  may  then 
be  placed  in  position  and  rammed  up  to  the  height  of  the 
riser  with  molding  material,  using  a  wooden  pattern  for  the 
riser  opening.  When  this  has  been  completed  the  whole  mold 
box,  pattern  and  all,  is  turned  over  and  the  bottom  half  of 
the  mold  box  rammed,  inserting  a  wooden  riser  pattern  in 
a  similar  way  to  the  first  half.  This  bottom  half  is  then  rapped 
slightly  and  lifted  from  the  pattern.  Then  by  rapping  the 
pattern  it  may  be  lifted  from  the  other  half  of  the  mold  box. 
After  removing  the  riser  pattern  the  molds  are  ready  to  be 
placed  on  the  rails  to  be  welded,  but  before  doing  so  the  space 
between  the  lip  and  the  ball  of  those  rail  sections  should  be 


WELDING  COMPROMISE  RAIL  JOINTS 


405 


rammed  flush  with  molding  material.  "When  the  boxes  are 
adjusted  they  should  be  luted  carefully  with  fireclay  around 
the  outside  edges  between  the  mold  and  the  rail  to  guard 


FIG.  64. — Welded  Compromise  Joint  Between  T-Eail  and  Grooved  Rail. 


FIG.  65. — Welded   Compromise   Joint   Between   Two   T-Rails,   Showing 

False  Lip. 

against  any  run  out  of  Thermit  steel.    The  joint  can  then  be 
preheated  and  poured  in  the  regular  way. 

This  method  will  be  found  to  save  considerable  time  over 
waxing  each  joint  separately,  and  the  two  short-rail  sections 


406  GAS  TORCH  AND  THERMIT   WELDING 

can  be  used  as  a  pattern  for  any  number  of  molds.  If  both 
right-hand  and  left-hand  compromise  joints  are  required  the 
same  pattern  and  mold  boxes  can  be  used  by  simply  discon- 
necting and  rearranging  for  either  right  or  left.  A  welded 
compromise  joint  between  a  grooved  and  a  T-rail  is  shown  in 
Fig.  64. 

Where  a  compromise  joint  is  to  be  welded  between  two 
T-rails  as  shown  in  Fig.  65  the  same  method  can  be  used  except 
that  in  this  case  it  is  necessary  to  arrange  for  a  false  lip  to 
be  cast  out  of  Thermit  steel  similar  to  the  lip  of  a  grooved 
rail.  In  other  words  the  Thermit-steel  collar  must  be  carried 
around  each  side  of  the  head  and  on  one  side  must  be  shaped 
in  a  corresponding  manner  to  the  lip  of  a  groove  rail.  This 
is  necessary  because  when  the  metal  begins  to  cool  and  con- 
tract there  must  be  an  equal  shrinkage  force  on  each  side  of 
the  insert  extending  to  the  top  of  the  head  tending  to  draw 
the  rails  together,  otherwise  the  insert  will  not  be  thoroughly 
butt-welded  into  the  head. 

THE  CLARK  JOINT 

Shortly  after  the  development  of  the  Thermit  rail- welding 
process;  Charles  H.  Clark,  chief  engineer  of  the  Cleveland 


TIG.  66. — Completed  Clark  Joint. 

Railway  Co.,  perfected  a  joint  known  -as  the  "Clark  joint," 

which  has  proved  exceedingly  successful  in  Cleveland  and  other 

Eastern  cities  where  many  thousand  joints  have  been  installed. 

In  its  original  form  it  consisted  of  a  combination  of  splice 


WELDING  COMPROMISE  RAIL  JOINTS 


407 


bars  and  Thermit  steel,  it  being  Mr.  Clark's  opinion  that  the 
head  of  the  rail  could  be  supported  by  using  plates  that  would 


FIG.  67  —Open  Mold  and  Crucible  in  Position  for  Making  Clark  Joint. 


FIG.  68.— Completed  Modified  Clark  Joint,  Showing  Weld  of  Base. 


come  under  the  ball  of  the  rail.     Furthermore,  in  order  to 
hold  the  rail  rigid  he  considered  it  important  that  there  should 


408  GAS  TORCH  AND  THERMIT  WELDING 

be  no  play  in  the  bolts,  so  the  holes  in  the  plates  and  rails 
were  drilled  round  and  machine  bolts  used  after  reaming  for 
a  drive  fit.  In  order  to  keep  the  bolts  and  plates  from  working 
loose  and  to  afford  bonding  between  the  rails  a  Thermit-steel 
shoe  was  cast  around  the  base  as  shown  in  Fig.  66. 

In  practice  the  rails  and  splice  bars  are  drilled  with  holes 
Vie  in-  less  in  diameter  than  the  bolt  to  be  used.     The  splice 


4   I  > 


Fi<?.  69. — Section  through  Modified  Clark  Joint.     It  will  be  Noticed  that 
the  Lower  Part  of  the  Bail  and  Fish  Plates  are  entirely  Amalgamated. 

bar  is  then  applied  in  the  ordinary  way  and  held  in  place  by 
a  couple  of  temporary  bolts,  a  drift  pin  being  driven  into  one 
hole  each  side  of  the  joint  to  keep  the  rails  in  position.  The 
remaining  holes  are  then  reamed  with  straight-end  cutting 
reamers,  after  which  the  machined  bolts  are  driven  and  tight- 
ened up  in  the  usual  manner.  After  preheating  the  rail  ends 
the  Thermit  steel  is  run  into  an  open  mold  surrounding  the 
lower  part  of  the  rails  as  illustrated  in  Fig.  67. 


WELDING  COMPROMISE  RAIL  JOINTS 


409 


In  the  latest  type  of  Clark  joint  rivets  are  substituted  for 
the  machined  bolts,  the  riveting  being  accomplished  by  a 
pneumatic  riveter  suspended  from  the  rear  end  of  a  flat  car 
carrying  an  air  compressor. 

A  modification  of  the  Clark  joint,  shown  in  Fig.  68,  has 
been  adopted  with  marked  success  by  the  United  Railways  and 
Electric  Co.,  Baltimore,  and  is  also  being  used  on  other 
properties. 

The  object  of  the  modification  was  to  obtain  a  larger  weld 


FIG.  70. — Appliances  in  Position  for  Welding  Third  Bail. 

of  the  base,  and  in  order  to  do  this  the  Thermit  steel  was 
poured  into  an  inclosed  mold  box  instead  of  into  an  open  mold 
and  the  rail  ends  were  preheated  to  a  red  heat  with  the  molds 
in  place  before  the  Thermit  charge  was  ignited.  Furthermore, 
the  design  of  the  fish  plates  is  somewhat  changed,  these  being 
of  special  design  1  in.  in  thickness  and  32  in.  long  and  being 
so  formed  as  to  fit  snugly  the  contour  of  the  head  and  base 
of  the  rail.  At  the  same  time  they  provide  a  minimum  amount 
of  space  between  the  web  of  the  rail  and  the  vertical  sides 


410 


GAS  TORCH  AND  THERMIT  WELDING 


of  the  fish  plates.  The  channel  bars  and  rails  are  of  the  same 
kind  of  steel  (high  carbon)  and  both  are  punched  at  the  mill 
with  ten  iyi6-in.  holes,  spaced  3  in.  centers  and  beginning 
2  in.  from  the  end  of  the  rail. 


FIG.  71. — A  Welded-Up  Cross-Over. 


FIG.  72. — Motor  Case  with  Broken  Lug  Previous  to  Welding. 

The  joint  has  been  applied  thus  far  exclusively  for  7-in. 
girder  groove  rails  weighing  103  Ib.  per  yard.  These  7-in. 
girder  sections  are  undercut  by  the  manufacturers  1/16  in.  so 
as  to  provide  a  space  of  -J  in.  at  the  base  when  the  rail  heads 
are  butted.  This  procedure  more  effectively  enables  the 


WELDING  COMPROMISE  RAIL  JOINTS 


411 


Thermit  steel  to  weld  the  rail  and  fish  plates  into  a  solid  mass 
at  the  joints,  as  shown  in  the  section,  Fig.  69. 

Welding  the  Third,  or  Conductor,  Rail.— The  welding  of 
the  third  rail  has  been  carried  on  more  extensively  abroad  than 
in  the  United  States.  This  is  especially  true  of  France,  where 
se-veral  thousand  joints  have  been  welded  for  the  Metropolitan 
Railway  and  others  in  the  neighborhood  of  Paris  where  this 
method  of  bonding  is  now  standard  practice. 

In  making  these  welds  in  France  the  base  and  flange  only 
of  the  rail  was  welded  with  Thermit  steel. 

As  a  great  deal  of  third  rail,  both  here  and  abroad,  is  used 


FIG.  73. — Motor  Case  Welded  and  Eeady  for  Service. 

in  tunnels  and  subways,  it  is  not  necessary  to  make  any  provi- 
sion in  such  cases  for  expansion  and  contraction,  it  having 
been  found  from  practical  experience  that  the  temperature 
changes  seldom  exceed  25  or  26  deg.  F.  These  are  the  figures 
that  were  determined  by  experiment  in  the  subways  controlled 
by  the  Metropolitan  Eailway  of  Paris.  In  cases,  however, 
where  the  third  rail  is  laid  in  open  stretches  of  track  where 
it  will  come  under  the  full  influence  of  atmospheric  changes 
in  temperature  it  is  of  course  necessary  to  provide  suitable 
means  for  taking  care  of  the  expansion  and  contraction,  and 
this  can  be  easily  done  by  installing  an  expansion  joint  at 
regular  intervals. 

Welding  third  rails  has  advantages  that  need  hardly  be 


412  GAS  TORCH  AND   THERMIT  WELDING 

enlarged  upon,  providing,  as  it  does,  for  a  uniform  electrical 
conductivity  of  the  rail  in  question  and  a  method  of  bonding 
which  will  not  deteriorate. 

A  Thermit  outfit  in  position  for  welding  a  third  rail  is 
shown  in  Fig.  70. 

A  very  simple  way  to  make  cross-overs  of  any  desired  form 
is  shown  in  Fig.  71.  The  rails  are  cut,  shaped  and  then 
Thermit  welded  together  and  then  the  surfaces  are  ground. 


FIG.  74. — Weld  on  Broken  Truck  Frame. 

The  result  is  as  smooth  and  solid  a  cross-over  as  it  is  possible 
to  make.  This  is  suggestive  of  many  other  similar  uses. 

The  same  outfit  required  for  welding  compromise  joints 
can  be  used  most  advantageously  for  welding  motor  cases  and 
truck  frames.  The  process  offers  special  advantages  for  such 
repairs,  owing  to  the  fact  that  the  collar,  or  reinforcement  of 
Thermit  steel,  which  is  fused  around  the  weld  may  be  made 
heavy  enough  to  insure  against  future  breakage. 

In  Fig.  72  is  shown  a  broken  motor  case,  and  in  Fig.  73  a 
welded  one.  A  welded  truck  frame  is  shown  in  Fig.  74. 


CHAPTER    VIII 
WELDING  CAST  IRON  AND  OTHER  PARTS 

The  Thermit  process,  while  adapted  to  the  welding  of  cast 
iron,  cannot  be  used  on  all  cast-iron  welds  owing  to  the  diffi- 
culty in  many  cases  of  allowing  properly  for  the  shrinkage 
of  the  metal  in  the  weld  when  cooling.  The  Thermit  steel 
contracts  twice  as  much  as  the  cast  iron,  so  that  in  certain 
constructions  shrinkage  strains  will  be  set  up  in  the  weld 
causing  cracks.  This  difference  in  shrinkage  often  makes  it 
impractical  to  weld  long  cracks  in  thin  sections.  As  a  general 
rule  we  should  say  that  if  the  length  of  crack  is  more  than 
eight  times  the  thickness  of  the  material  a  Thermit  weld  should 
not  be  attempted,  because  on  account  of  the  difference  in 
shrinkage  along  the  line  of  the  fracture  small  hair-line  cracks 
will  appear  perpendicular  to  the  line  of  the  fracture.  These 
cracks,  however,  being  perpendicular  to  the  line  of  the  weld 
are  often  therefore  of  little  consequence  and  do  not  interfere 
with  the  strength  of  the  weld. 

It  is  also  not  usually  feasible  to  weld  cracks  in  cast-iron 
cylinders,  pots,  kettles  and  similar  castings.  Where  there  is 
a  clean  break  between  two  sections  or  where  the  section  to 
be  welded  can  be  completely  cut  through  and  can  be  separated 
a  sufficient  amount  to  allow  for  the  contraction  in  the  weld, 
and  also  where  the  length  of  the  weld  is  not  more  than  eight 
times  the  thickness  of  the  material,  a  Thermit  weld  would 
be  entirely  practical  and  can  be  made  in  exactly  the  same  way 
as  outlined  for  the  welding  of  wrought-iron  and  steel  sections. 

In  cases  where  the  crack  can  be  opened  up  mechanically 
or  by  heating  a  parallel  part  to  a  dull  red  a  weld  may  be 
made,  but  it  must  be  remembered  that  expansion  gained  in 
this  way  must  be  a  little  more  than  the  expansion  of  the  parts 
next  to  the  weld  during  the  preheating. 

Care  should  be  taken  in  preheating  for  cast-iron  welds  not 

413 


414  GAS  TORCH  AND  THERMIT  WELDING 

to  heat  the  sections  too  hot;  a  dull  red  is  sufficient.  One 
should  be  careful  to  keep  the  heat  going  until  the  mold  is 
thoroughly  dried  out. 

The  mixture  of  Thermit  for  the  weld  should  be  different 
than  for  wrought  iron  and  steel,  and  for  this  purpose  the 
special  mixture  known  as  cast-iron  Thermit  is  recommended. 
This  consists  of  plain  Thermit  with  which  is  mixed  3  per  cent 
ferrosilicon  and  20  per  cent  mild-steel  punchings,  i.e.,  to 
every  100  Ib.  of  plain  Thermit  is  added  3  Ib.  of  ferrosilicon 
and  20  Ib.  of  punchings.  This  gives  the  best  results  on  cast 
iron  and  produces  a  homogeneous  metal  in  the  weld. 

Welds  on  cast  iron  are  a  little  more  difficult  to  machine 
than  welds  on  wrought  iron  and  steel,  as  the  metal  along  the 
line  of  junction  of  the  Thermit  metal  and  the  cast  iron  is  apt 
to  be  a  trifle  hard  due  to  the  absorption  of  carbon  from  the 
cast  iron.  This  objection  is  not  a  serious  one,  however,  and 
hundreds  of  welds  have  been  completed  with  the  most  satis- 
factory results. 

Examples  of  Cast-iron  Welds. — In  order  to  show  the  pos- 
sibilities of  welding  various  cast-iron  pieces  with  Thermit  a 
few  examples  taken  from  actual  practice  are  given. 

Fig.  75  shows  how  a  new  jaw  was  burned  onto  the  frame 
of  a  heavy  shear,  in  the  shops  of  the  Raleigh  Iron  Works  Co., 
Raleigh,  N.  C.  The  job  was  done  in  1906  and  the  machine 
is  still  in  service.  This  machine  was  designed  for  shearing 
ljX6-in.  bars,  producing  an  enormous  strain  on  the  jaws. 
A  large  part  of  the  corner  of  the  lower  jaw,  weighing  about 
75  Ib.,  broke  off.  It  then  became  a  question  of  getting  a  new 
frame  or  burning  on  a  new  jaw  corner,  which  would  require 
the  fusing  of  a  surface  about  1  sq.  ft.  in  area  in  order  to  obtain 
a  thorough  union.  It  was  finally -decided  to  try  Thermit.  The 
surface  of  the  break  was  chiseled  off  for  the  reason  that  a 
cast-iron  break  is  usually  glazed  with  graphitic  carbon.  The 
mold  was  then  put  in  place  and  well  luted  with  fire  clay  where 
there  was  any  danger  of  leakage.  Moist  sand  was  also  rammed 
around  the  mold  and  other  parts  as  a  further  precaution.  The 
surface  of  the  fracture  and  the  stock  around  the  jaw  was  then 
heated  through  the  gates  and  risers  by  means  of  gas  jets, 
in  order  that  the  casting  might  be  thoroughly  heated  and  all 
moisture  driven  out.  The  gas  torches  were  kept  in  action 


WELDING   CAST   IRON   AND   OTHER    PARTS 


415 


several  hours.  A  crucible  containing  175  Ib.  of  Thermit  was 
then  put  in  position  for  tapping  into  the  mold.  After  the 
reaction  the  Thermit  steel  was  run  into  the  mold  and  at  once 
fused  the  entire  surface  of  the  fracture.  In  the  meantime  a 


FIG.  75. — New  Jaw  Burned  to  Frame  Casting  of  Heavy  Shear. 

ladle  of  molten  cast  iron  containing  about  600  Ib.  of  metal  was 
held  in  readiness  and  Avas  superheated  by  means  of  a  Thermit 
semi-steel  can.  As  soon  as  possible  after  pouring  the  Thermit, 
this  cast  iron  was  poured  into  the  second  gate,  shown  at  the 
front  of  the  jaw,  and  this  forced  the  Thermit  steel  out  of  the 


416  GAS  TORCH  AND  THERMIT  WELDING 

mold  after  it  had  served  its  purpose  in  bringing  the  surface 
of  the  jaw  to  a  welding  or  fusing  heat.  The  result  was  a 
new  corner  of  cast  iron  burned  onto  the  old  jaw.  The  illus- 
tration shows  the  two  gates  and  four  risers  before  they  were 
trimmed  off.  In  Reactions  for  the  fourth  quarter  of  1917 
W.  J.  Musick,  blacksmith  foreman  of  the  St.  Louis  shops  of 
the  Missouri  Pacific  R.R.  wrote : 

We  recently  had  one  of  our  steam  hammers  break  through  both 
sides  of  the  frame  and  through  the  throat,  the  fracture  being  61  in. 
long.  This  hammer  was  so  badly  broken  that  it  seemed  as  though 
it  were  doomed  for  the  scrap  pile. 

A  new  ;  team  hammer  was  ordered,  but  in  the  meantime  it  was 
decided  to  try  to  repair  the  old  one  with  Thermit.  The  weld  was 
made  and  a  successful  repair  was  accomplished,  resulting  in  saving 
a  considerable  amount  of  money. 

We  have  also  welded  a  cast-iron  engine  bed  for  the  Helmbacher 
Rolling  Mill  Co.  The  bed  of  this  engine  is  32  in.  high  and  12  in.  across 
the  top.  The  mill  was  only  shut  down  24  hours  while  the  repair 
was  being  made. 

Master  Mechanic  George  M.  Stone,  writing  in  the  same 
publication,  says: 

I  think  your  readers  will  be  interested  in  the  accompanying  illus- 
trations of  Thermit  welds  which  have  been  made  by  me  in  the  shops 
of  the  Chicago,  Rock  Island  and  Pacific  Railroad,  Chickasha,  Okla., 
arid  I  would  like  to  call  particular  attention  to  the  welding  of  valve 
seats  on  locomotive  cylinders,  which  I  consider  an  exceptionally  good 
piece  Of  work  in  view  of  the  fact  that  these  are  cast-iron  cylinders. 
The  manner  in  which  we  handled  the  work  was  as  follows: 

The  ports  of  the  cylinders  were  cracked  through  from  the  steam 
port  to  the  exhaust  port.  A  Thermit  weld  was  made  on  these  cylinders, 
and  in  order  to  do  this  the  entire  cylinder  was  cut  loose  from  the 
frame  and  smoke  arch*  of  the  locomotive.  The  pistons  were  removed 
from  the  cylinders,  as  well  as  the  cylinder  heads  both  front  and  back. 
The  cylinder  was  then  preheated  with  a  slow  wood  fire  and  welded 
with  Thermit. 

We  have  also  had  very  good  success  with  the  welding  of  spokes 
in  driving-wheel  centers  and  the  \velding  of  main  frames  on  one  of 
our  heaviest  classes  of  engines  in  freight  service. 

These  instances  show  that  in  many  cases  the  success  or 
failure  of  a  cast-iron  welding  job  is  merely  a  matter  of  good 
judgment.  As  in  other  kinds  of  welds,  expansion  and  con- 
traction must  be  allowed  for,  and  in  many  cases  where  a  purely 


WELDING  CAST  IRON  AND  OTHER  PARTS 


417 


Thermit  weld  would  be  out  of  the  question,  owing  to  the 
difference  in  contraction  of  cast  iron  and  Thermit  steel,  the 
Thermit  may  be  used  merely  to  bring  the  broken  surface  up 
to  a  fusing  heat  and  then  molten  cast  iron  may  be  burned 
on,  as  was  done  with  the  shear  jaw  previously  mentioned. 

The   illustrations  here   given  show  how   Thermit  welding 
may  be  applied  to  various  cast-iron  machine  parts.     Fig.  76 


FIG.  76, — Weld   on   48-In.,    68  000-Lb.,   Cast   Iron   Blooming-Mill    Housing. 
About  3500-Lb.  of  Eailroad  Thermit  Used. 

shows  a  weld  on  a  48-in.  blooming  mill  housing,  which  weighed 
68,000  Ib.  Approximately  3500  Ib.  of  railroad  Thermit  was 
used.  Fig.  77  shows  a  weld  on  a  rolling-mill  bed  made  for 
the  Waclark  Wire  Co.,  Elizabeth,  N.  J.  The  weld  shown  in 
Fig.  78  was  on  a  25-ton  nail-machine  housing,  and  650  Ib.  of 
Thermit  was  used.  Another  housing  weld  on  a  knuckle  machine 
made  by  the  Standard  Parts  Co.,  Cleveland,  is  shown  in  Fig. 


418 


GAS  TORCH  AND  THERMIT  WELDING 


79.    Many  times  breaks  on  machine-tool  parts  could  be  repaired 
in  the  same  way. 

Welding  High-Speed  Steel  to  Machinery  Steel. — The  largest 
weld  ever  made,  up  to  January,  1919,  was  a  cast-iron  weld 
on  a  blooming-mill  shear  at  the  plant  of  the  Pittsburgh  Steel 


FIG.  77. — Cast-Iron  Boiling  Mill  Base  Repaired  for  the  Waclark  \Vire  Co., 

Elizabeth,  N.  J. 


FIG.  78. — Repair  on  a  25-Ton  Nail-Machine  Housing. 

Co.  The  broken  piece  was  of  irregular  shape  approximately 
37  in.  wide  by  5  ft.  6  in.  long  and  weighed  about  3000  Ib. 
Five  No.  10  crucibles  were  used  for  the  job. 

Sometimes  it  is  advisable  to  weld  tool  or  high-speed  steel 
to  a  mild-steel  bar 'or  shank.  This  is  perfectly  feasible  for 
special  drills,  reamers,  boring  bars  or  special  tools  of  various 


WELDING  CAST  IRON  AND  OTHER  PARTS 


419 


kinds.  Where  only  one  or  two  jobs  are  to  be  done  ordinary 
welding  by  the  wax-core  method  may  be  employed,  but  where 
many  pieces  are  to  be  welded  it  will  pay  to  make  molds.  A 


p.i  IN  iimimm^^——!  i  i  

FIG>  79. — Cast-Iron  Housing  of  Knuckle  Machine,  Welded  by  the  Standard 
Parts  Co.,  Cleveland,  Ohio. 


FIG.  80. — Machinery  Steel  and  High-Speed  Steel  Ready  to  Clamp  Mold. 

mold  for  welding  round  bars  together  is  shown  in  Fig.  80. 
The  pattern  and  mold  box  for  this  are  shown  in  Fig.  81. 

High-speed  steel  blades  may  also  be  welded  into  large  or 


420  GAS  TORCH  AND  THERMIT  WELDING 

emergency  job  reamers  in  a  comparatively  short  time.  For 
this  purpose  a  cylinder  is  bored  out  slightly  larger  than  the 
hole  to  be  reamed.  The  blades  for  the  reamer  are  placed  inside 
this  cylinder  and  wedged  into  their  proper  places.  Tin  or 
wooden  spacing  pieces  may  be  used  for  this  if  they  are  so 
placed  as  to  be  removed  after  the  wax  hardens.  After  the 
blades  are  fixed  in  position  another  cylinder  or  piece  of  pipe 
is  centered  inside  the  blades,  allowing  space  between  the  blades 
and  this  cylinder  according  to  the  size  of  the  reamer  being 
made.  Wax  is  next  poured  into  the  spaces  between  the  blades 


FIQ.  81.— Sheet-Iron  Mold   Box  and   Wooden   Pattern. 

and  the  inner  cylinder.  After  it  is  removed  from  the  outer 
cylinder  and  the  wax  hardens,  enough  of  it  is  trimmed  away 
between  the  blades  to  allow  for  chip  space.  The  wax  matrix 
with  the  blades  in  place  is  then  rammed  up  in  a  mold.  The 
inner  cylinder  is  then  warmed  slightly  and  removed.  A  steel 
shank  is  next  inserted  and  centered  correctly.  The  wax  is 
now  melted  out  and  the  Thermit  steel  run  in,  welding  the 
blades  securely  to  the  steel  shank.  A  wax  matrix,  with  blades 
and  inner  cylinder  in  place,  is  shown  in  Pig.  82.  In  this 
illustration  the  wax  has  been  cut  away  between  the  blades 
and  the  assembly  is  ready  to  be  put  into  the  mold  box  and 


WELDING  CAST  IRON  AND  OTHER  PARTS 


421 


be  rammed  up.     When  the  work  is  cool  it  is  centered  and 
the  blades  ground  for  size  and  clearance. 

A  helical  reamer  with  inserted  high-speed  steel  blades  is 
shown  in  Fig.  83.    This  reamer  was  made  by  T.  O.  Martin, 


FIG.  82.— High-Speed   Steel   Cotters   Held   in   Wax   Pattern   with  Hollow 

Steel  Core 


TIG.  83 —Helical  Inserted-Blade  Reamer  Made  by  the  Thermit  Process. 

blacksmith  foreman  of  the  Elinois  Central  R.R.  shops  at  Jack- 
son, Tenn. 

Preheaters  for  Thermit  Work.— As  practically  all  welds 
in  ordinary  practice,  except  those  on  pipe,  require  preheating 


422  GAS  TORCH  AND  THERMIT  WELDING 

it  is  well  to  use  heaters  made  for  the  purpose  wherever  possible. 
In  some  shops  gas- burning  torches  supplied  with  compressed 
air  may  be  used.  Many  shops,  however,  have  neither  gas 
torches  nor  compressed  air.  This  method  is  not  practicable 
on  outdoor  welds.  Crude-oil  heaters  should  not  be  used  at 
all,  on  account  of  their  tendency  to  deposit  carbon  or  other 
matter  on  the  surfaces  to  be  welded,  thereby  causing  imperfect 
welds.  In  order  to  make  the  preheating  work  as  easy  and 
convenient  as  possible  the  Metal  and  Thermit  Corporation 
makes  the  preheaters  here  shown.  Fig.  84  shows  two  kinds, 
a  single  and  a  double  burner.  For  infrequent  or  small  jobs 
the  single  burner,  which  may  be  fitted  with  a  flaming  burner 
also,  will  probably  answer  the  purpose.  Where  a  number  of 

TABLE  V. — COST  OF  THERMIT  AND  APPARATUS  FOR  GENERAL  WELDING 

Gross  Lb. 
Shipping  Weight     Cost 

Railroad  Thermit  (50-lb.  boxes  only) 67£  $17.50 

Plain  Thermit  (50-lb.  boxes  only) 59  17.00 

Cast-iron  Thermit  (50-lb.  boxes  only) 70J  17.50 

Ignition  powder  (£-lb.  cans) .45 

Yellow  wax,  per  pound . .  .35 

Punchings,  per  pound . .  .025 

Special  molding  material   (300  Ib. ) 340  4.00 

Fire  clay  (300  Ib.  net) 340  3.50 

Fire  brick,  per  barrel  (300  Ib.  net ) 340  4.00 

Kiln-dried  silica  sand  (300  Ib.  net ) 340  3.50 

Single-burner  preheater .. 200  50.00 

Double-burner  preheater 225  75.00 

Flaming-burner  attachment ...  3.00 

Magnesia  stones,  No.  1 .15 

Magnesia  stones,  No.  3 .20 

Magnesia  thimbles,  No.  1 .10 

Magnesia  thimbles,  No.  3 .15 

Magnesia  tar,  about  400  Ib.  net 450  .06 

Plugging  material,  No.  2  package .10 

Automatic  crucibles  (with  caps  and  rings) 40  4.00 

Automatic  crucible,  No.  2 60  5.50 

Automatic  crucible,  No.  5 150  11.00 

Automatic  crucible,  No.  10 775  60.00 

Cast-iron  relining  cone,  No.  1 50  5.00 

Cast-iron  relining  cone,  No.  5 150  12,00 

Cast-iron  relining  cone,  No.  10 600  40.00 

Tripods,  Nos,  1  to  7,  weights  11  to  65  Ib. $2.50  to  9.00 


WELDING      CAST  IRON  AND   OTHER  PARTS  423 


FIG.  84. — Single-Burner   and  Double-Burner   Preheaters,   Using   Either 
Gasoline  or  Kerosene. 


FIG.  85.— Rail  Preheater  That  Will  Heat  Four  Joints  at  Once. 


424 


GAS  TORCH  AND  THERMIT  WELDING 


welds  are  to  be  made,  however,  the  double-burner  apparatus 
should  be  selected.  In  these  illustrations  A  is  the  place  to 
attach  the  hose  from  the  compressed-air  supply ;  B  is  the  valve 
for  regulating  the  pressure  on  the  surface  of  the  fuel;  C  is  a 
tube  which  runs  within  a  few  inches  of  the  bottom  of  the 
tank;  D  is  the  needle  valve  which  controls  the  fuel  to  the 
burner;  E  is  the  air  pressure  control  to  the  burner;  F  is  a 
check  valve  which  prevents  back  fire ;  G  are  torches  or  burner 
pipes;  H  is  a  flaming  burner.  The  small  tank  on  the  left  side 
is  a  water  separator  for  the  compressed-air  supply. 

TABLE  VI. — COST    OF    MATERIALS    AND    APPLIANCES    FOR    PIPE    WELDING 
STANDARD  WEIGHT  PIPE. 


I'RI 

nt  or  WEI 

DINO  pom 

"IONS 

Inside 
Diam- 
eter, 
Inches 

100 
or 

Over 
100  and 
Less 

Over 
500  and 
Less 

1000 
or 

Price 
of 

Mold 

Pri« 
Sic 
Cruc 

and 

5  Of 

ibles 

Price  and 
Size  of 
Tongs. 

Pric 

c8L 

eand 
eof 
unp« 

Price  ai 
^ 

>d  Sue  of 

a? 

Lena 

than 

than 

More 

500 

1000 

H 

$0.36 

$0.32 

$0.27 

$0.19 

$0.75 

No.  21 

No.  2] 

No.  1] 

No.    1 

54 

.44 

.40 

.36 

.26 

.75 

2 

2 

1 
1^ 
1H 

.60 
.78 
.90 

.56 
.74 

.86 

.55 
.69 

.84 

.39 

.60 
.75 

1.00 
1.25 
1.50 

2 
2 
2 

$1.75 

2  $2.00 

2 

$20  00 

$35.00 

2 

1.03 

.99 

.97 

.90 

1.75 

2 

2J 

I* 

1.50 
2.16 

1.46 
2.12 

1.43 
2.09 

1.35 
2.06 

2.00 
2.25 

31 
31 

3.00 

3/  2'50 

l» 

3.06 
4.63 

3.02 
4.59 

2.99 
4.56 

2.96 
4.50 

2.50 
2.75 

4 

4j 

4.75 

4}  3.25 

21 
2J 

>  25.00' 

2^ 
2J 

60.00 

EXTRA  HEAVY  PIPE 


H 

$0.45 

$0.42 

$0.37 

$0.29 

$0.75 

2 

2 

1 

% 

.54 

.48 

.42 

.34 

.75 

2 

2 

1 

1 

.72 

.67 

.62 

.56 

1.00 

2 

$1.75 

2 

$2.00 

1 

JBl 

.90 
1.14 

.86 
1.10 

.84 
1.05 

.75 

.98 

1.25 
1.50 

2 
2 

2 
2 

.00 

$35  00 

2 

1.78 

1.75 

1.71 

1.65 

1.75 

3 

3.00 

3 

2.50 

2H 

2.94 

2.90 

2.86 

2.80 

2.00 

4 

4 

•: 

3 

4.23 

4.20 

4.16 

4.10 

2  25 

4 

4  75 

4 

3.25 

JH 

5.43 
6.22 

5.40 
6.18 

5.36 
6.14 

5.10 
6.08 

2.50 
2.75 

\ 

7.50 

5 

4.50 

.00 

2 

2J 

-  60.00 

DOUBIJE  EXTRA  HEAVY  PIPE 


M 

$0.93 
1.08 

$0.90 
1.04 

$0.86 
1.02 

$0.81 
96 

$1.50 
1.75 

N°'2}$1,75 

No.  2 

o 

$2.00 

No.  1 
1 

No.  1 
1 

1 

1.20 

1.16 

1.14 

1.08 

2.00 

3\  s  nn 

2 

1 

1 

JH 

1.49 
2.14 

1.43 
2.08 

1.41 
2.03 

1.36 
1.94 

2.25 
2.50 

3J3.00 

41    A    TK 

3 
3 

2.50 

1 

r.oo 

1 
1 

$35  00 

2 

3.82 

3.73 

3.71 

3.68 

2.75 

4l 

4    3.25 

1 

2^ 

7.30 

7.27 

7.24 

7.20 

3.00 

'         5\7  «tt 

1 

1 

3 

10.60 

10.57 

10,54 

10.50 

3.50 

5J7.50 

5}4.50 

lj 

1 

Fig.  85  shows  a  four-burner  portable  apparatus  used  largely 
for   rail-welding  work.      It    carries   its   own   air   compressor, 


WELDING  CAST  IRON   AND  OTHER  PARTS  425 

which  may  be  run  by  attaching  to  a  trolley  wire  or  to  some 
other  electric-current  supply.  All  of  these  burners  use  either 
gasoline  or  kerosene. 

Cost  of  Thermit  Welds  and  Apparatus. — There  are  many 
factors  which  enter  into  the  calculation  of  the  cost  of  Thermit 
welding  and  the  apparatus.  Where  a  single  weld  is  to  be 
made  and  the  shop  man  has  to  buy  the  apparatus,  materials 
and  do  the  work  himself,  the  cost  will  naturally  be  higher 
than  where  several  welds  are  to  be  made  or  where  he  can 
hire  it  done.  There  are  so  many  places  now  making  a  specialty 
of  Thermit  welding  that  in  ordinary  circumstances  it  is  usually 
better  to  have  them  do  the  work  on  large  jobs  than  for  inex- 
perienced men  to  undertake  the  work. 

Data  for  the  appropriate  cost  of  various  jobs  have  been 
given  in  tables  and  specifications  throughout  the  article,  but 
in  order  to  give  those  responsible  for  repair  or  other  welding 
work,  as  exact  information  as  possible  on  which  to  base  their 
calculations,  the  accompanying  tables  are  included.  These 
are  taken  from  the  price  list  of  the  Metal  and  Thermit  Cor- 
poration, published  June  15,  1918,  and  of  course  are  subject 
to  changes.  These  quotations  are  f.o.b.  Jersey  City,  N.  J. 
Table  V  gives  prices  for  general  welding  materials,  and  Table 
VI  for  pipe  work.  It  will  be  noted  that  some  of  the  quotations 
in  this  last  table  do  not  exactly  agree  with  figures  given  in 
the  table  of  comparative  costs  of  Thermit  welded  and 
mechanically-joined  pipe,  but  it  should  be  borne  in  mind  that 
the  comparative  table  gives  averages  only,  and  is  also  subject 
to  variations  in  cost  of  labor  and  materials. 


INDEX 


Acetone,  26 

— ,  capacity  of,  for  acetylene,  27 

—  injurious  to  weld,  28 
— ,  nature  of,  26,  27 

Acetylene  and  Welding  Journal,  144 
— ,  cubic  feet  per  pound,  28 

—  cylinder  filling  material,  27 
,  capacity  of,  27 

— ,  danger  point  of,  26 
— ,  discovery  of,  1 

— ,  estimating  amount   of,   in  cylin- 
der, 28 
— ,  explosive  limits  of,  6 

—  gas  from  pound  of  carbide,  29 

—  generator,         Davis-Bournonville 

"Navy  type,"  32 
— ,  heat  units  in,  3 
— ,  ignition  temperature  of,  6 

—  manifolds,  *118 

,  Davis  positive-pressure,  de- 
scription of  mechanism,  32 

,  positive-pressure,  *30 

,  details  of  300  Ib.  size  of,  *31 

,  low-pressure  type,  phantom 

view,  *42 

,  Oxweld  portable  pressure 

type,  36,  *39 

repairs,  45 

sets,  dimensions  and  weights 

of,  37 

—  generators,  capacity  of,  29 
— ,  low  pressure,  41,  *42,  *43 

,  Navy  type,  size  of,  35 

-,  positive-pressure,  capacity,  29 

,  pressure  limit  of,  30 

,  standard  rating,  29 

,  the  three  types  of,  28 

,  types,  28,  29 


Acetylene  plant  layout,  *34 

-  —/'Navy  type,"  *33 

—  positive-pressure  generator,  29 

—  pressure  generator,  first,  2 
— ,  production  of,  26 

— ,  specific  gravity  of,  6 
Action  of  cutting  torch,  257 
Adaptors  for  regulator  and  cylinder 

connections,  *103 
Additions,  use  of  Thermit,  400 
Air  chisel  for  welding  work,  *187 

-  Eeduction  Sales  Co.,  92 

—  screen  for  cooling,  201,  *202 
Airco-Vulcan     combination    welding 

and  cutting  torch,  *91 
Alexander  Milburn  Co.,  92 
All-steel  welding  truck,  *35 
Allowance    for    expansion    and    con- 
traction, 154 

Aluminum  gear  case,  repair  of,  205, 
*207 

—  oxide,  melting  point  of,  174 
— ,  preheating,   175 

— ,  purity  of,  173,  174 

—  sodium  fluoride,  174 
— ,  welding,  173 
fluxes,  174 

American  Blaugas  Corporation,  5 

—  Machinist,    208,    215,    231,    236, 

244,  247 

—  Society    for    Testing    Materials, 

rail  specifications  of,  391 

—  Welding  Society,  267 
Amount  of  Thermit  to  use,  345 

used  in  roll  welding,  379 

Anchor  welds,  *385,  *386 

Angle   iron   used   in   welding,    *225, 

*226 
Apparatus,  cost  of  Thermit,  425 


427 


428 


INDEX 


Applications  of  Thermit  fusion  weld- 
ing, 338 

Areas  of  drill  holes,  65 

Armour  Institute  of  Technology,  51 

Asbestos  and  molasses  strips,  use  of, 
395,  *396 

Assembly  for  welding  and  cutting, 
*105,  *109,  *111,  *117,  *126,  *127, 
*128 

Automatic  crucible  for  Thermit,  *333 

Automobile  cylinder,  broken,  *189 

welding,  164,  *165 

" Autogenous  Welding,"  1 

Autogenous   Welding,  272 

B 

Back-pressure  valves,  *124,  125 

Backward  welding,  144,  *147,  *148, 
*149 

Baking  Thermit  crucible,  335 

Barium  peroxide  for  igniting  Ther- 
mit, 326 

Bastian-Blessing  Co.,  64,  90 

Battery,  storage,  burning,   152,   153 

Benzine  vapor,  5 

Benzol  vapor,  5 

Bethlehem  Shipbuilding  Corp. 
Acetylene  plant,  *33 

Beveling  boiler  flanges,  *289 

Bisulphates  of  sodium  and  potas- 
sium, 174 

Blaugas,  discovery  of,  5 

— ,  explosive  limits  of,  6 

— , —  range  of,  5 

— ,  makers  of,  5 

— ,  method  of  selling,  5 

Blau,  Herman,  5 

Blooming-mill  housing  Thermit  weld, 
*417 

Blowing  a  hole  through  a  plate,  *261 

Boiling  point  of  liquid  oxygen,  10 
nitrogen,    10 

Bond,  rail,  *204,  *205 
-  welding  outfit,  *205 

Bosses,  forming,  *143 

Bournonville,  Eugene,  2 

Brass  and  bronze  welding,  176 

Brennan,  A.  F.,  216 


Bronze  and  brass  welding,  176 
Buckeye    carbide    feeding    mechan- 
ism, 36,  *38 

-  oxygen  generator,  *11 

—  portable  oxygen  generator,  *12 
Building  up  a  weld,  *141 
Burning  battery  cell  connectois,  153 
— ,  lead,  data  on,  153 

-  out  carbon,  302 
Butt  joints,  lead,  151 
welding  plates,  *134 


Calcium  carbide,  2,  26 
— ,  how  handled,  26 
Calculating  amount  of  Thermit,  346 

welding  gases,  63,  64 

Calmbach,  G.  M.,  200 

Camograph    cutting    machine,    *286, 

*287 
Capacity  of  Oxweld  generators,  40 

oxygen  cylinders,  9 

Carbide,    amount    of    acetylene   pro- 
duced,  29 

—  feed,  Buckeye,  36,  *38 
— ,  size  of,  29 
Carbo-Hydrogen  Co.,  87,  262 

-  cutting  torches,  87,  *88,  *89 
Carbon  burning,  302 

—  outfit,  *304 

—  electrode   and   oxygen   jet  torch, 

*274 

—  monoxide,  2 

Card  for  cost  keeping,  *301,  *303 

Carhart,  H.  A.,  231 

Carnegie  Steel  Co.,  208 

Carrying  case  for  cutting  or  weld- 
ing outfits,  *120,  *122 

Cartridge,  Thermalene,  46,  47,  *48, 
50 

Cast,  aluminum,  purity  of,  173,  174 

-  iron,  cutting,  267 

,  samples  of  cut,  *272 

Thermit,  composition  of,  321 

to  steel,  welding,  179 

welding,  177,  178 

,  with    Thermit,    413,    *415, 

*417,  *418,  *419 


INDEX 


429 


Chain  links,  building  up,  205,  *207 
Chapman,  E.  E.,  274 
Characteristics    of    welding    flames, 

*107,   *113,   *114 
Charging     an     acetylene    generator, 

44 
Chemical   oxygen  generator,   *11 

—  symboi  lor  acetylene,  1 

calcium   carbide,   2 

Chemistry      of      the      oxy-acetylene 

flame,  *107,  110 

Chlorate   of   potash    oxygen    genera- 
tors, size  of,  12 

process,  amount  of  oxygen 

produced,  10 

for  oxygen,  10 

Chlorides     of      sodium,      potassium, 

lithium,  174 

Chrome  steel  welding,  186 
Circular  cutting,  284 
City  gas,  ignition  temperature  of,  6 
Clark,  Charles  H.,  406 

—  joint,  the,  *406 

,  the  modified,  *407,  *408,  409 

Cleveland     Eailway     Co.,      Thermit 

welded  joints  for,  406 
Coal  gas,  explosive  limits  of,  6 

,  specific  gravity  of,  6 

Collars,  building  up,  *143 
Colors  of  tank  and  hose,  101 
Combination  torches  for  cutting  and 
welding,  *91,  92 

—  welding  and  cutting  torch,   Mil- 

burn,  *91,  92 
Commercial  Gas  Co.,  274 
Compromise     rail     joints,     welding, 

403,  *405 

Conductivity  and  oxidation,  169 
Connecting     up     and     lighting     the 

torch,  104,  *105,  109 
Containers   for   poison-gas,    welding, 

*230,  *232 

Contraction  and  expansion,  154 
Cooling  devices,  201,  *202 

—  oven,  Wiederwax,  *161 

—  work,  160 

Conveyor  roller  welding,  *227,  *228, 
229 


Copper,  flux  for,  180 

—  to  steel,  welding,  180 

-  welding,  179 

Corsair,  welded  anchor  of,  *386,  389 
Corunna,  sternpost  weld  on,  *389 
Cost  keeping  form,  *301,  *303 
— ,  —  track  of,  302 

-  of  cutting,  266,  267 

oxy-hydrogen  cutting,  276,  276 

Thermit  apparatus,  422 

-  pipe  welds,  329,  330,  424 

-  welds,  424,  425 

welding  large  cylinders,  211 

per  foot,  204 

Cracks,  how  to  locate,  364 

Crank    case,    broken    and    repaired. 

*191 

-  welding,  *225,  *226 
Crankshaft  welding  jig  for  Thermit 
work,  *361 

-  repair,  192,  *193 

-  welding,  *223,  *224,  225 
Crankshafts,  welding  with  Thermit, 

359,  *363,  *364 

Crane,  portable,  for  welding  shop, 
*299 

— ,  trolley,  and  hoist,  *296 

C.,  E.  I.  &  P.  E,  E.  shop  work, 
416 

Crosshead  welding  with  Thermit,  351 

Cross-over  rails  welded  with  Ther- 
mit, *410 

Crucible,  baking  Thermit,  335 

—  holder  for  locomotive  work,  *355 
— ,  lining  Thermit,  *333,  334 

— ,  Thermit  automatic,  *333 

— ,  tapping  Thermit,  *334 

Crucibles,  details  of  Thermit,  *333, 
337 

Crude  oil  or  kerosene  preheater, 
*157 

Gumming,  J.  E.,  202 

Current  required  for  separating  oxy- 
gen and  hydrogen,  16,  20 

Cut,  size  of,  made  by  a  cutting 
torch,  75 

Cutting-  a  rivet  head,  *261 

—  action  of  a  gas  torch,  74,  75 


430 


INDEX 


Cutting  and  welding  outfits,  116, 
*117,  119,  *120,  *122,  *126, 
*127,  *128,  *129 

—  cast  iron,  267 

— ,  circular,  284,  285,  288,  289,  292 
— ,  cost  of,  266,  267 

—  data,  85 

— ,  learning  how  to  do,  *258,  *259, 
*260 

—  machines,  *278,  *279,  *280,  *281, 

*282,    *283,    *284,   *285,   *286, 
*287,    *288,    *289,    *290,    291,  | 
*292,  *293,  *294 
— ,  manifolds  for,  *118 

—  speed  of  gas  torch,  83 

—  steel  risers,  85 

—  tests,  data  on,  86 
-  tips,  *84 

—  — ,  Davis-Bournonville,  *77 

—  tools,  Messer,  *84 

—  torch,  Airco-Vulcan,   *91 
,  first,  3 

for   ship   work,   Oxweld,    *87, 

82 

,  how  the,  acts,  257 

made  by  General  Welding  and 

Equipment   Co.,   *84 

,  Milburn,  *91,  92 

,  Eego,  *90 

,  rivet -head,  80 

,  staybolt,  *81,  82 

that    preheats    oxygen,    *273, 

*274 

,  Torchweld,  *92,  *93 

,  underwater,  *94 

—  torches,  74,  *75,  *76,  *79 

— ,  carbo-hydrogen,   87,   *88,   *89 

,  Davis-Bournonville,'  *75,  *76 

,  gas  pressures  used,  78 

,  Imperial,  86,  *88 

,  machine,  *76,  78 

,  Oxweld,  *79 

—  under  water,  94 

— ,  depth  of,  94 

—  unit,  typical,  *117 

—  with  a  guide,  *262 
oxy-hydrogen,  274 

the     gas     torch,     hand,     257, 


*258,      *259,     *260,      *261, 
*262,   *263,   *266,   267,  269 
"Gut-weld"  torch,  Milburn,  *91,  92 
Cylinder,  amount  of  acetylene  in,  28 
— ,  automobile,  broken,  *189 
— ,  welded,  *190 
— ,  welding,   164,   *165 

—  connection  adaptors,  *103 

-  grooved  for  welding,  *188 
— ,  Liberty,  tacking  jacket,  *233 
— ,  preheating  low-pressure,  *210 

-  pressures  for  acetylene,  27 

-  welded,  *189 

—  welding,    a    remarkable    job    of, 

208,  *209,  *210,  *211,  *212 

,  cost  of,  bll 

— , —  low-pressure,    *211 

— ,  wrecked  low-pressure,   *209 

Cylinders,  acetylene,  filling  material, 

27 
— ,  — ,  temperature  of,  27 

-  for  oxygen  and  hydrogen,  capac- 

ity of,  15 

,  weight  of,  27 

— ,  motor,     removing    carbon     from, 

302 
— ,  sheet-metal,     jigs     for     welding, 

*227,  *228,  *229,  231 
—,—,  welding,  *240,  *241,   *242 


Data  on  lead  burning,  153 

Davis-Bournonville  Co.,  15,  239,  267, 
272,  279,  280,  286 

cutting  machines,  *279,  *280, 

*281,  *282,  *284,  *285, 
*286,  *287,  *289,  *290, 
*292,  *293*  *294 

torches,  *75,  *76 

,  gas  pressures  for,   78 

Duograph,    239,    *240,    *241, 

*242 

hand   truck  for  welding  out- 
fit, *35 

tf  Navy  type ' '  acetylene  gen- 
erator, 32 

positive-pressure         acetylene 

generators,   29 


INDEX 


431 


Davis-Bournonville    underwater    cut- 
ting torch,    *94 

water-cooled   welding  torches, 

tji-a-       *57 
welding  torches,  55,  *56,  *57 

—  Acetylene  Co.,  29 

—  acetylene   generator,   size   of,   32 
— ,  Augustine,  2 

—  electrolyzer  cell,  15 

— ,  details  of,  *17 
Davy,  Edmund,  1 
Decarbonizing  motor  cylinders,  302 
Dentist's  torch,  *129 
Details  of  Thermit  mold  box,   *340 
Discovery  of  acetylene,  1 

oxygen,  9 

Dissociation  temperature  of  water,  4 

Driers,  acetylene,  Oxweld,  size,  40 

Drigas,  5 

— ,  explosive  limits  of,  6 

— ,  method  of  selling,  5 

— ,  explosive   range,   5 

Drill  hole  areas,  65 

Drums,    sheet-metal,    welding,    *240, 

.  *241,   *242,   *243 
Duograph,  the,  239,  *240,  *2*1,  *242 

E 
Edison  Storage  Battery  Co.,  244 

—  welding      machine      for      oblong 

seams,  *245 
Electric    blower   type    of   preheater, 

*158,  *159 
Electrical  properties  of  oxygen  and 

hydrogen,  13 
Electrolytic  hydrogen,  purity  of,  14 

—  method,  principles  of,  13 

—  oxygen,   10 
,  purity  of,  14 

—  Oxy-Hydrogen  Laboratories,  Inc., 

24 
Electrolyzer  cell,  Davis,  15 

,  — ,  description  of,  18 

— ' — , — ,  details  of,  *17 

,  International,  *19 

,  — ,  current  used,  20 

,  — ,  details  of,  *20 

,  — ,  principles  of,  22 


Electrolyzer  cells,  space  for  battery 

of,  25 

— ,  details  of  Levin,  *25 
— ,  Levin,  24 
— ,  — ,  principles  of,  24 
-  plant  layout,   *22,  *23 
Electrolyzers,  currents  used  in,  16 
— ,  Davis,  sizes  of,  16 
— ,  gas  capacity  of,  16 
Elements,  separation  of,  173 
Emergency  cutting  outfit,  *122 

—  Fleet       Corporation       tests      on 

strength        of        oxy-acetylene 

welds,  *310,  311 
Endothermic  acetylene,  3 
Estimating  amount  of  acetylene  in 

cylinder,  28 

Eveready  instruction  book,  150 
Examples  of  welding  jobs,  187 

methods,  *139 

Expansion   allowance   on   locomotive 

frame,  *200 

—  and  contraction,  154 
Explosive  limits  of  acetylene,  6 

blaugas,  6 

coal  gas,  6 

drigas,  6 

hydrogen,  6 

thermalene,  6 

welding  gases,  5 

—  range  of  blaugas,  5 
drigas,  5 

Equipment    of    welding    shop,    295, 
296,  *297,  *298,  *299,  *300 

—  rules,  305 


Feeding    mechanism,    Buckeye    car- 
bide, 36 

Fery,  F.  M.,  319 

Field  of  gas-torch  welding  and  cut- 
ting, 7 
Filling    rod,    using   the,    137,    *138, 

*147,  *148,   *149 
-  up  a  hole,  142 
First  acetylene  pressure  generator,  2 

—  cutting  torch,  3 

—  uses  of  the  gas-torch,  3 


432 


INDEX 


First  welding  gas-torch,  2 

Fixtures     for    welding,     *219,    221, 

*222,  *223,  *224,  *225,  *226,  *227, 

*228,  *229,  *230,  *232,  *233,  *234, 

'*235,  *236,  *237,  *238. 
Flame     characteristics,     *107,  *113, 

*114 

— ,  oxy-acetylene,  3 
— ,  — ,  chemistry  of,  *107,  110 
Fluorides     of     sodium,     potassium, 

aluminum-sodium,  174 
Flow,  indicator  for  gas,  128,  *130 
Flux  for  aluminum  castings,  175 
brass  and  bronze,  176 

-  cast  iron,  177 

-  copper,  180 

Fluxes  for  welding  aluminum,  174 

—  used   in   welding,    169 
Fouche,  Edmond,  2 

Frame,    rudder,   ready   for   welding, 

*201 

— ,  — ,  repair,   *208 
— ,  welded  locomotive,  *199 

—  welding,  locomotive,  *200 

Fuel  used   in  chemical  oxygen  gen- 
erators, 12 
Furnace  for  preheating  large  pinion, 

*372 

— ,  preheating,  on  iron  table,  *156 
— ,  — ,  using  charcoal,  *156 
Fusion    and    plastic    welding    with 

Thermit,  319 

—  welding,  application  of  Thermit, 

338 

of  heavy  sections  with  Ther- 
mit, 333 

G 
Gate    patterns    for    Thermit    molds, 

*341 

Gauthier-Ely,  2 
X3ear  case,  repair  of,  205,  *207 

—  teeth,   welding,   *144,   *168 

^        iiij      J.y  / 
Generating     plant,     "Navy     type" 

acetylene,    Bethlehem,    *33 
Generator,  charging  acetylene,  44 
— ,  details  of  positive-pressure,  *31 


Generator,      positive-pressure,      sta 
tionary  type,  *30 

—  repairs,  acetylene,  45 

—  sizes,  Oxweld  low-pressure,  44 
Generators,  acetylene,  pressure  limit 

of,  30 

— ,  — ,  the  three  types  &f>  28 
—,—, types,  88,  29 
— ,  Davis      acetylene,       sizes      and 

weights,  37 
Gages    for    gas    pressures,    95,    *96, 

*98,  *99,  MOO,  M01,  M02 
Galvanized  iron  welding,  186 
''Gas  Torch,"  1 
Gas,  acetylene,  amount  from  pound 

of  carbide,  29 

—  capacity   of  Davis   electrolyzers, 

16 

—  consumption  in  cutting,  83 
lead  burning,  153 

of      carbo-hydrogen      cutting 

torches,  84 

—  cutting  torches,  74,  *75,  *76,  *79 

—  flow  indicator,  127 

—  pressure  in  lead  burning,  153 
regulators,  95,  *96,  *98,  *99, 

MOO,  M01,  M02 

used   in    Thermalene   welding 

torches,  72 

—  pressures  for  cutting  torches,  78 
Davis-Bournonville  welding 

torches,  59 

Imperial  oxy-hydrogen 

torches,   62 

three-way     welding 

torches,  63 

Oxweld  torches,  68 

welding  torches,  68 

Prest-O-Lite       welding 

torches,  61 

Thermalene  welding,  72 

welding    torches,    59,    61, 

62,  63,  68,  72 
—  used  in  cutting,  83 
-  torch,  field  of,  7 

welding    and    cutting    outfits, 

116,  M17,  119,  M20,  M22, 
M26,  M27,  M28»  *129 


INDEX 


433 


Gas  torch  welding  speed,  61,  68 

—  torches  used  for  welding,  54,  *55, 

*56,    *57,    *60,    *62,    *66,    *67, 
*69,  *70,  *71,  *72 
Gases,  calculating  amount  of  weld- 
ing, 63,  64 

— ,  explosive  limits  of,  5 
— ,  ignition  temperatures  of,  6 
Gasometer,  Oxweld,  size  and  capac- 
ity, 40 
General  Electric  Co.,  292 

—  Welding  and  Equipment  Co.,  84 
welding  torch,  *60, 

61 

Generator,    Oxweld   acetylene,   port- 
able type,  *39 

Generators,  Oxweld  duplex,  *43 
— ,  — ,  sizes  of,  40 
— ,  Thermalene,    45,    *46,    *51,    *52, 

53 

German  silver  welding,  186 
Gold  welding,  186 
Goldschmidt,  Hans,  317 

—  Thermit  Co.,  318 

Goggles    for    gas-torch    work,    120, 

*121 

Grating,  welding,  155,  *162,  163 
Great  Western  cutter,  *288 

-  Cutting  &  Welding  Co.,  279, 

288 

Grinding  machine  for  rail  work,  400, 
*401 

,  use  of,  187 

Grooved  cylinder  ready  for  welding, 

*188 

Grooving  with  an  air  chisel,  *187 
Guide  for  cutting,  *262 
— ,  yoke  welding  with  Thermit,  *352 
Guides  for  welding,   *310 

H 

Hales,  Stephen,  9 

Hastings,-  G.  A.,  215 

Heat  of  Thermit,  318,  319 

—  units  in  acetylene,  3 
Heating,  improper,  *163 

—  torches,  *157,  *158,  *159 
,  using,  *157 


Helmbacher  Boiling  Mill  Co.,  416 
Henderson  Motorcycle  Co.,  227 
High  speed  tips,  welding,  213,  *214, 

215,  *216,  *217,  *219 
welded     to     machinery     steel 

with    Thermit,    418,    *419, 

*420 

History  and  nature  of  Thermit,  317 
Hole,  filling  a  large,  176 
— ,  blowing  a,  through  a  plate,  *261 
Holder,     crucible,     for     locomotive 

work,  *355 

Holding  the  gas  torch,  *132 
Holes,  filling,   142 
Holograph  cutting  machine,  *285 
Hooks,  making  large,  *265 
Hose,  color  of,  101 
Howard,  H.,  201 
Hydrate  Engineering  Corp.,  127 
Hydrex  gas  flow  indicator,  128,  *130 
Hydrogen     and      acetylene      flames 

compared,  13 

oxygen  flame,  heat  of,  13 

,  rate    of    electrolytic    pro- 
duction, 16 

—  by  the  electrolytic  method,  13 

—  compressed    air   flame    character- 

istics, *114 

—  cylinders,  pressure  of,  15 
,  size  and  weight  of,  15 

—  electrolytic,  purity  of,  14 
— ,  explosive  limits  of,   6 

-  gas,  4 

— ,  ignition  temperature  of,  6 
— ,  specific  gravity  of,  6 


Ignition  temperature  of  acetylene,  6 

city  gas,  6 

gases,  6 

Igniting  Thermit,  317,  326,  344 
Illinois  Central  E.  E.  shops,  421 
Illuminating  gas,  5 
Imperial   Brass   Mfg.   Co.,   86,   259, 
260 

—  cutting  torches,  86,  *88 

—  decarbonizing  outfit,  *304 


434 


INDEX 


Imperial  preheating  torch,  *158 

—  three-way  gas  outfit,  *111 
welding  torch,  63 

-  welding  torch,  *62,  63 
Improper  heating,  *163 
Injector,  type  gas  torch,  54,  *55 
Inlet  pipe,   Liberty  motor,  welding, 

*234 
Insert   rail  welds,    392,    *393,    *396, 

*397,  *398,  *399 

Instructions  for  lead  burning,  150 
International  cell,  capacity  of,  20 

—  cells,  group  of,  *21 

—  Oxygen  Co.,   19 
generator,   18 

Ireland  &  Mathews  Mfg.  Co.,  236 
Iron  table  with  firebrick  top,   *156, 
*159 


Jaw,     locomotive     frame,     welding 

with  Thermit,  *348 
Jeweler's  torch,  *129 
Jig  for  welding  tool  tips,  *219 
Jigs  and  fixtures  for  welding,  *219, 
221,  *222,  *223,  *224,  *225,  *226, 
*227,  *228,  *229,  *230,  *232,  *233, 
*234,  *235,  *236,  *237,  *238 
Jottrand  oxygen  jet  cutting  patent,  3 
Journal  of  Acetylene  Welding,  176 

K 

Kautny,  4 

Keeping  track  of  costs,  302 
Keithley,  F.  N.,  369 
Kerf  of  a  cutting  torch,  75 
Kerosene  preheater,   *157 
Kettle,  welding  a  large,  192,  *193 
Kinds  of  Thermit,  320 
Kirk,  J.  W.,  274 

Knuckle     machine     repaired     with 
Thermit,  *419 


Ladle  hooks,  making  large,  265 
Lap  joints,  lead,  151 
Lathe  bed  repairs,  *195 


Lavoisier,  9 

Layout  of  acetylene  plant,   "Navy 
type,  *34 

welding  shop,  295,  *297 

Lead  burning,   125,  126 

-  data,  153 

,  gas  consumption   in,   153 

,  —  pressure  used  in,  153 

instructions,   150 

outfits,   *126 

—  sticks,  or  rods,  151 

—  welding  or  "burning,"  181 
Leaks,  testing  for,  105 

Learning  to  weld  with  a  gas-torch, 

131 

Le  Chatelier,  2 
Le  Khone  motor,  237 
Levin,  I.   H.,  24 

—  generator  for  oxygen  and  hydro- 

gen, 24 

Liberty  motor  manifold  work,  *236, 
*237,  *238 

-  work,  231,  *233,  *234,  *235 
Lighting  low-pressure  torch,  Oxweld, 

109 

-  the  torch,  104,  109 
Lincoln  Motor  Co.,  231 
Linde  Air  Products  Co.,  9,  312 
-,  Carl,  2 

—  process,  2 

Lining  Thermit  crucible,  *333,  334 
Links,  chain,  building  up,  205,  *207 
Lithium  chloride,  174 
Liquid  air  process,  oxygen  by  the,  9 
Lloyd  tube  welding  patent,  250 
Locating  cracks,  364 
Locomotive  crosshead,  welding  with 
Thermit,   *351 

—  frame,     heating     zones     on,     for 

Thermit  welding,  *347 
leg,    welding,    with    Thermit, 

*348 
splice,  welding  with  Thermit, 

*349,  *353 
— ,  welded,  *199 

-  welding,  *200 

-  with  Thermit,  *347 

—  mud  ring  with  Thermit,  *350 


INDEX 


435 


Locomotive    rocker    shaft,     welding 

with  Thermit,  *352 
-   wheel  welding  with  Thermit,  *354 
Low-pressure    acetylene    generators, 
operation  of,  41 

-  torch,  lighting  the,  109 

-  welding  torch,  54,  *55 

-  torches,  Oxweld,  *66,  *67, 

*69,  *70 
Ludwick,  Herbert  V.,  218 


M 


Machine  cutting  torches,  *76,  78 
—  for  circular  seams,  *244 
-  facing  pipe  ends,  322 
welding  oblong  seams,  *245 

-  tools,   welding,    193,    *194,    *195, 

*196 
— ,  torches  for  welding,   *253 

-  welding  torches,  *57,  *64,  *70 
Machinery  steel  welded  to  high  speed 

steel  with  Thermit,  418,  *419,  *420 
Machines  for  cutting,  *278,  *279, 
*280,  *281,  *282,  *283, 
*284,  *285,  *286,  *287, 
*288,  *289,  *290,  291,  *292, 
*293,  *294 

welding,      239,      *240,      *241,  j 

*242,     *243,      *244,      *245, 
*246,  *247,  *248,  249,  *250, 
*251,   252 
Macleod  Co.,  The,  11 

-  Co.  's  carbide  feed,  36,  *38 
Magnesia   stone   thimbles   for   Ther- 
mit crucibles,  *333,  336 

Magnesium      powder     for      igniting 

Thermit,  317 
Magnetograph  cutting  machine,  284, 

*285 
Making  allowance  for  expansion  and 

contraction,  154 
Malcher,  L.  M.,  208 
Malleable  iron  welding,  181 
Manganese  dioxide,  uses  of,  10 

-  steel  welding,  186 

Magnesia     tar     used     for     Thermit 
crucible,  334 


Manifold  welding,  *226,  *227,  *230, 

*232,  *236,  *238 
Manifolds,  *118 
Martin,  T.  O.,  421 
McCormack,     calculations     of,     for 

specific  gravity,  6 
McManamy,  Frank,  309 
Melting    points    of    various    metals, 

170 
Messer  cutting  tools,  *84 

-  Mfg.  Co.,  *70,  *71,  82 

-  welding  torch,  *70 

Metals    and     Thermit    Corporation, 

318,  422,  425 
— ,  commonly  welded,  properties  of, 

170 
Metropolitan  Railway  of  Paris,  rails 

welded  for,  with  Thermit,  411 
Miller,  S.  W.,  162 
Modified  Clark  joint,  *407,  *408,  409 
Moisson,  H.,  1 
Mold  for  pipe  welding,  *324,  *325, 

*328 

welding  high  speed  and  ma- 
chinery steel  with  Thermit, 
"'419,  *420 

-  box,  details  of  Thermit,  *340 
— ,  ramming  Thermit,  340 

— ,  Thermit,  for  heavy  sections,  *338 
Molds,    Thermit,    *323,    *324,    *325, 

*328,    *338,    *342,    *348,   *349, 

*350,  *367 

— ,  wax-pattern,  *338,  339 
Monel  metal  welding,  183 
Motor  case  welding  with  Thermit, 

*410,  *411 

-  cylinder  welding,  164,  *165 
Motorcycle  manifold  welding,   *22G, 

*227 
Movement   for  welding,   *133,   *137, 

*147,  *148,  *149 
Mud  ring,  locomotive,  welding  with 

Thermit,  *350 
Musick,  W.  J.,  416 

N 

Nail   machine    repaired    with    Ther 
mit,  *418 


436 


INDEX 


Napolitan,  F.  J.,  267,  269 
Nashville,  wheel  shaft  weld  on,  *386, 

389 
National    Safety    Council    rules    for 

gas-torch  users,  305 
' '  Navy   type ' '   acetylene   generator, 
32 

—  generators,  size  of,  35 

plant  layout,  *34 

Necks  on  pinions,  welding  new,  374, 

*376,  *378,  *380,  *381,  *382,  *384 
Neutral  flame,  3 
New  York  Shipbuilding  Yards,  work 

in,  *281 
Nickel  steel  welding,  186 

—  welding,    183 
"Nicking"  billets,  262 
Nitrogen  and  oxygen,  separation  of, 

10 

— ,  boiling  point  of,   10 
North  American  Mfg.  Co.,  160 
-  preheater,   *159 

O 

Olympia,    welded    anchor    davit    of, 

*385,  389 

Operation  rules,  306 
Osceola,  wheel  shaft  weld  on,  *387, 

390 

Outfits  for  welding  and  cutting,  116, 
*117,  119,  *120,  *122,  *123,  *126, 
*127,  *128,  *129 

Outlet  pipe,  Liberty  motor,  weld- 
ing, *235 

Oval  hole  cutting  machine,  *288 
Oven,  Cooling,  Wiederwax,   *161 
Oxidation  and  conductivity,  169 
Oxide,  how  to  deal  with,  171 
Oxweld  Acetylene  Co.,  150,  208,  209, 
236,  247 

—  —  Co.  's    portable    pressure-type 

acetylene  generator,  36,  *39 

—  cutting  data,  83 

—  cutting  machine,  *278 
torches,   *79 

—  duplex  acetylene  generators,  *43 

—  gasometer,  size  and  capacity,  40 


Oxweld  low-pressure  generator  sizes 

and  capacities,  44 
-  torch,  *66,  *67,  *69,  *70 

-  outfit,  a  complete,  *123 

-  preheating  torches,   *157 

—  pressure    type    acetylene    gener- 

ators, 40 

-  regulators,  95,  *96,  97,  *98,  *99, 

*100 

—  rivet-head  cutting  torch,  *80 

-  sheet-metal  welding  torch,  *69 

-  torches,   gas  pressures   for  weld- 

ing, 68 

—  water-cooled      welding      torches, 

*69,  *70 
Oxy-acetylene    flame    characteristic, 

*107 
-  temperature,  3 

-  welds,  strength  of,  311 
Oxygen-acetylene-hydrogen     welding 

pressures,  63 

— ,  amount   obtained  from  cholorate 
of  potash,  10 

—  and  hydrogen  electrolyzer  plant, 

*22 

rate    of    electrolytic    pro- 
duction, 16 

nitrogen  in  the  air,  9 

— ,  separation  of,  10 

—  by  the  electrolytic  method,  13 

—  liquid  air  process,  9 
— ,  chlorate    of    potash    process,    10 

—  cylinder  pressure,  9 

-  cylinders,  sizes  of,  9 
— ,  discovery  of,  9 

— ,  electrolytic,  purity  of,  14 

—  generator,  chemical,  *11 

—  — ,  International,   18 

—  illuminating  gas  flame  character- 

istics, *114 

-  jet  cutting  patent,  3 
— ,  Linde  method  patent,  2 
— ,  liquid,  boiling  point  of,  10 

-  manifolds,  *118 
— ,  purity  of,  10 

—  regulator,  details  of,  *96,  97 
— ,  using,  for  carbon  burning,  302 


INDEX 


437 


Oxygraph     cutting     machine,     292, 

*293,  *294 

Oxy-hydrogen  cutting,  274 
-  cutting  pressures,  86,  87 

—  flame  characteristics,  *113 
,  temperature  of,  4 

—  for  cutting,   13 

—  welding  flame,  uses  of,  13 
pressures,   62 

torch,  *71,  *72 


Patents  on  Thermit,  317 

Patterns  for  Thermit  mold  gate  and 

riser,  *341 
Phelps,  C.  C.,  236 
Picard,  2 

Pinion,  a  Thermit  welded,  *373 
— ,  preheating,  for  Thermit  welding, 
*371 

—  teeth,    replacing    with    Thermit, 

365,  *367 

Pinions,  welding  new  necks  on,  374, 
*376,  *378,  *380,  *381,  *382,  *384 
Pipe  facing  machine,  *322 

—  mold   for   welding  vertical   pipe, 

*328 
-  welding,  *222,  223,  *228 

-  materials,  *323 

-  mold,  *324,  *325,  *328 

-  outfit,  324 

-  with  Thermit,  cost  of,  424 

—  welds,  cost  of  Thermit,  329 

— ,  strength  of,  Linde  tests,  312 
Pit    for    Thermit    welding    roll    and 

pinion  necks,  *376 
Pittsburgh  Steel  Co.,  418 
Planer  bed  repair,  *194 
Plant  layout   for  electrolyzers,    *22, 

*23 

Plastic     and     fusion     welding    with 
Thermit,  319 

—  process  welds,  322 
Plate,  speed  of  welding,  204 
Plumley,  Stuart,  267 

Pneumatic  chisel  for  welding  work, 

*187 
Pods,  building  up,  205,  *206 


Poison-gas  containers,  welding,  *230, 

*232 

Portable  electric  blower  type  of  pre- 
heater,  *158,  *159 

—  pressure    type    acetylene    gener- 

ator, 36 

Position  for  cutting,  *258 
Positive-pressure     acetylene     gener- 
ator, 29 

,  first   one   made,  29 

Potassium  bisulphate,  174 

—  chloride,  174 

-  fluoride,  174 

—  hydroxide,  uses  of,  17 

-  sulphate,  174 

Pouring  Thermit  into  pipe  mold, 
*328 

Preheater,  electric  blower  type  of, 
*158,  *159 

— ,  North  American,  *159 

— ,  Tyler,  158 

— ,  Wiederwax,  *161 

Preheaters,  *156,  *157,  *158,  *159, 
*161 

— ,  gasoline  and  kerosene,  for  Ther- 
mit work,  *423,  424 

Preheating  and  welding  method, 
*191 

—  aluminum,  175 

—  for  Thermit  welding,   *371,  421, 

*423 
rail  welds,  397,  *399 

—  motor  cylinders,  *165 

-  Thermit  mold,  343 

—  torches,  Oxweld,  *157 

-  zones  indicated,  *155,  *162,  *163, 

*165 

Preparing  Thermit  mold,  343 
Pressure   gages,    gas,    95,    *96,    *97, 

*98,   *99,   *100,   *101,   *102 
— ,  gas,  for  welding  torches,  59,  61, 

62,  63,  68,  72 

—  of  carbo-hydrogen  for  cutting,  89 

gas  in  lead  burning,  153 

oxygen  in  cylinders,  9 

Pressures,  gas,  in  cutting,  83 

—  used  for  underwater  cutting,  94 
in  three-way  gas  system,  87 


438 


INDEX 


Prest-OLite   tool   welding   practice, 
*216 

—  welding  torch,  58,  *60 
Priestly,  9 

Production  of  oxygen,  9 
welding  gases,  9 

Propeller  blade  beveled  for  welding, 

*188 
Properties      of      metals      commonly 

welded,  170 

Pryor,  Frederick  L.,  329 
Puget  Sound  Navy  Yard,  94 
Pulley,    welded   in    12   places,    *198, 

199 

— ,  welding,  *163 
Pump,    building   up   worn   parts   of, 

205,  *206 
Punch    press    frame    repairs,    *194,  | 

*195,  *196 

Purifier,  acetylene,  Oxweld,  size,  40 
Purity  of  oxygen.  10 
"Putting  on"  metal,  143 
Pyrograph    cutting    machine,    *289, 

*290,  291,  *292 

Q 

Quantity  of  Thermit  to  use,  345 

wax   used   for  Thermit   weld 

ing,   346 

R 

Rack-feed  cutting  machine,  *280 
Radiagraph    cutting    machine,    280,  | 

*281 

Radius  cutting  attachment,  *263 
Rail  bonding,  204,  *205 

—  grinding   machine,   400,   401 

—  joints,  compromise,  welding,  403, 

*405 

—  preheater  for  heating  four  joints 

at  once,  *423 

—  specifications     for    difference    in 

height,  391 

—  welding  for  electric  systems,  391 

-  weld  patterns,  *394,  *395,  404 

-  welds,    insert,    392,    *393,    *396, 

*397,  *398,  *399 
Railograph  cutting  machine,  *282 


Railroad    Thermit,    composition    of, 

321 
Railway      Administration      welding 

rules,  309 

— ,  K.  C.  Southern,  200 
Raleigh  Iron  Works  Co.,  414 
Ramming  Thermit  mold,  340 
Reactions,  416 
Reamer,    inserted    blade,    made    by 

Thermit  process,  419,  *421 
Rego  cutting  torch,  *90 
-  welding  torch,  64,  *66 
Regulator  attached  to  gas-cylinder, 
*103 

—  connection  adaptors,  *103 
Regulators,  acetylene,  *100,  *102 
— ,  gas,     Davis-Bournonville,      *101, 

*102 

— ,  Oxweld,  95,  *96,  *97,  *98,  *99, 
*100 

—  oxygen,    95,    *96,    97,    *98,    *99, 

*101 

Restrained  weld,  *162 
Richards,  Joseph  W.,  318 
Richardson,  Capt.  D.,  144 
Riser   patterns    for    Thermit   molds, 

*341 

Risers,  cutting  steel,  85 
Rivet  cutting,  *261 
Rivet-head     cutting-torch,     Oxweld, 

*80 

Rochester  Welding  Works,  162 
Rocker  shaft  welding  with  Thermit, 

*352 

Rod,  size  of,  for  steel,  184 
— ,  using    the    welding,     137,    *138, 

*147,  *148,  *149 
— ,  welding,  for  cast  iron,  178 
Rolled  aluminum,  purity  of,  173 
Roller,  welding  sheet-metal,   *227 
Roll    neck    welding    with    Thermit, 

*367 

—  pods,  building  up,  205,  *206 
Rolling     mill     base     repaired     with 

Thermit,  *418 

Rolls  and  pinions,  welding  new  necks 
on,  374,  *376,  *378,  *380,  *381, 
*382,  *384 


INDEX 


439 


Rolls,  arrangement  of,  for  tube  weld- 
ing, 251,  *252 
Root     &     Vandervoort     Engineering 

Co.,  218 

Roulleau,  M.,  145 
Rules,  equipment,  305 

—  for  operation,  306 

welding,    U.    S.   Railway   Ad- 
ministration, 309 

Rudder    frame    ready    for    welding, 
*201 

repair,   *208 

Rules,  safety,  for  gas-torch  workers, 
305 

S 
Safety  rules  for   gas-torch  workers, 

305 
Schneider  works,  cutting  heavy  plate 

in,  *283 
Seam,  circular,  welding,  244 

—  contraction,    allowing    for,    *135, 

*136,  *137 

— ,  oblong,  welding,   *245 
Separation  of  elements,  173 
Shaft  welding,  *222,  223 

with    Thermit,    V-blocks    for, 

*361,  362 
Shear  arm,  welding,  *167 

—  jaw    burned    on    with    Thermit, 

*415 

Ship  plate  cutting,  *263 
Shop  layout,  295,  *297 
Silver,  German,  welding,   186 

-  welding,  186 

Sizes  of  oxygen  cylinders,  9 

Smith,  Elmer  H.,  274 

— ,  F.  M.,  247 

Sodium    bisulphate,    174 

—  chloride,  174 

-  fluoride,  174 

—  hydroxide,  use  of,  10 
,  uses  of,  17 

—  sulphate,  174 

Sawing  off  end  of  roll  neck  previous 

to  Thermit  welding,  *375 
Special  steel  welding,  185 
Specific  gravity  of  gases,  6 

—  heat  of  various  metals,  170 


Speed,  carbo-hydrogen  cutting,  89 

— ,  cutting,  of  gas  torch,   83 

— ,  machine,  for  welding  tubes,  255 

-  of  cutting,  263,  273 

— steel  risers,  85 

underwater,  94 

machine     cutting,     280,     283, 

284,  286,  289,  291,  292,  294 

oxy-hydrogen      cutting,      275, 

276 
-  plate   welding,  204 

welding  steel  and  sheet   iron 

cylinders,  231 

—  with  a  gas  torch,  61,  68 

Splice,    locomotive    frame,    welding 

with  Thermit,  *349,  *353 
Spreader     disk    for    tube    welding, 

*251,  *252 

Square  hole  cutting  machine,  *288 
Standard  Parts  Co.,  417,  419 
Starting  a  cut,  *258,  *259 
Staybolt  cutting  torch,  Oxweld,  *81, 

82 

Steel,  high  speed  and  alloy,  welding, 
185 

,  welding,   213 

— ,  Thermit,  composition  of,  318 

—  to  cast  iron,  179 

copper,   welding,   180 

-  welding,  183 

Sternpost  welds,  *387,  *388,  *389 

Stone  &  Webster  Corp.,  92 

— ,Geo.  M.,  416 

Storage  battery  burning,  152,  153 

Straight-line  cutting  machines,  *278, 

*279,  *283 

Strength    of    oxy-acetylene    welded 
pipe,  312 

welds,  311 

Thermit  welds,  318,  329,  331 

—  welded  tank,  203 
Sulphates  of  sodium  and  potassium, 
174 

T 

Table  for  welding  work,  *221 
— ,  iron,    with    firebrick    top,    *156, 

*159 
Tables,  welding,  *30Q 


440 


INDEX 


Tank  and  hose  colors,  101 

— ,  welded,  *203 

— ,  — ,  strength   of,    203 

-  welding  jig,  *229,  231 
Tapping   Thermit   crucible,   *334 
Temperature  of  oxy-acetylene  flame, 

3 

oxy-hydrogen  flame,   4 

Thermit,   318,  319 

Thermalene  flame,  3 

Tensile  strength  of  various  metals, 

170 

Tested,  kinds  of  welds,  *310 
Testing  for  gas  leaks,  105 
Tests  of  Welding  Committee,   *310, 

311 
Thermalene,  advantages  of,  52 

—  cartridge,   46,  47,  *48,  50 

—  Co.,  5,  45,  244,  246 
— ,  composition  of,  45 
— ,  discoverer  of,  5,  45 

— ,  explosive  limits  of,  6,  52 
— ,  first  description  of,  45 

—  flame,  temperature  of,  3,  51 

—  gas  welding  pressures,   72 

—  generators,  41,  45,  *46,  *51,  *52, 

53 

— ,  makers  of,  5,  45 
— ,  production  of,  49 
— ,  properties  of,  51,  52 
— ,  specific  gravity  of,  6 
Thermit  additions,  use  of,  400 
— ,  amount    of;    used    for    roll    and 

pinion  work,  379 
— , —  to  use,  345 

-  crucible,  333 

-  crucibles,  details  of,  *333,  337 
— ,  history  of,  317 

— ,  igniting,  317,   326 
— ,  kinds  of,  320 

—  molds,    *323,    *324,    *325,    *328, 

*338,    *342,    *348,    *349,   *350, 
*367 

—  patents,  317 

—  pipe  welding,  322 

-  plain,  railroad  and  cast-iron,  320 

—  plastic-process  welds,  322 

-  reaction,  318 


Thermit  steel,   composition   of,   318, 

320,  321 

— ,  temperature  of,  318,  319 
— ,  the  two  methods  of  using,  319 

—  welding   "don'ts,"    353 

-  welds,  strength  of,  318,  329,  331 
Theoretical    proportions    of    oxygen 

and  acetylene,  2 

Thimbles,  magnesia  stone,  for  Ther- 
mit crucibles,  333,  336 
Third  rail  welding,  *409,  411 
Three-way  gas  system,  pressure  used 
in,  87 

—  welding  torch,  Imperial,  63 

Tip,  preparing  to  weld,  *214,  *216, 

*217,  *219 
Tips,  cutting,  *77 

—  for    welding    torches,    *58,    *60, 

*67,  *70,  *71,  *72 
— ,  welding  on  high  speed  steel,  213, 

*214,  215,  *216,  *217,  *219 
Tire,  welding,  for  truck,  190,  *192 
Tool  welding,  213,  *214,  215,  *216, 
*217,  *219 

practice   of   Eoot   &    Vander- 

voort  Engineering  Co.,  *217, 
218 
Tooth  pattern,  making  a  wax,  *367, 

368 

Torch  arrangement  on  welding  ma- 
chine,  *241,   *243,   *244,   *245, 
*251,  *252 
— ,  carbon  electrode  and  oxygen  jet, 

*274 

— ,  cutting,  action  of,  257 
— ,—  with    the     hand,     257,     *258, 
*259,      *260,     *261,      *262, 
*263,  *266,  267,  269 
— ,  gas  and  air  preheating,  *158 
— ,  how  to  hold  the  gas,  *132 

-  motion,    *133,    *137,    *147,    *148, 

*149 
Torches,    combination     for    welding 

and  cutting,  *91,  *92,  *93 
— ,  cutting,  74,  *75,  *76,  *79 
— ,  heating,  *157,  *158,   *159 
— ,  water-cooled   machine,    for   weld- 
ing, *253 


INDEX 


441 


Torchweld  cutting  torch,  *93 

-  Equipment  Co.,  93 
Trouble,  sources  of  in  welding,  140 
Truck,    car,    welded    with    Thermit, 

*412 

— ,  motor,  welding,  *192 
Tube,  samples  of  welded,  *254 
—  welding     machines,     *246,     *247, 

*248,  249,  *250,  *251 
Tyler,  Mfg.  Co.,  159 
Types  of  acetylene  generators,  28 

welding  torches,  54,  *55 

Typical   oxy-acetylene   cutting   unit, 

*117 
Tyler,  preheater,  *158 

U 

United    Railways   and    Electric   Co., 

Thermit  welded  joints  for,  409 
Universal  cutting  machine,  *292 


V-blocks     for     shaft     welding    with 

Thermit,  *361,  362,  *363,  *364 
Valves,  back-pressure,  *124,  *125 
Vaporization  of  substances,  172 
Vanadium  steel  welding,  186 
Vautin,  Claude,  317 
Vertical  pipe,  welding  mold,  *328 
-  welds,  142 
Volumes    of    oxygen    and    acetylene 

used,  3 
—  —  oxy-hydrogen,  4 


W 

Waclark  Wire  (Jo.,  417,  418 
Water-cooled  cutting  torches,  Davis- 
Bournonville,  *76 

welding  torches,  Davis-Bourn  - 

onville,  *57 

torches,  Oxweld,   *69,   *70 

— ,  dissociation  of,  4 
—  jacket,      tacking,      for      Liberty 
motor,   *233 


Wax-pattern     molds     for     Thermit 
welding,  338,  *339 

-  tooth  pattern,  *367,  368 
Weiderwax,    preheater,    *161 
Weight  of  oxygen  cylinders,  10 

Thermit  apparatus,  422 

various  metals,   170 

Weld,  restrained,  *162 
Welding  aluminium,  173 

—  and  cutting,  field  of,  7 

—  outfits,     116,     *117,     119, 
*120,   *122,   *126,   *127, 
*128,  *129 
preheating  method,  *191 

-  backward,   144,  *147,  *148,  *149 

-  Committee  tests,  *310,  311 
Welding  Engineer,  200,  213,  274 

—  gases,  estimating  amount,  63,  64 
,  explosive  limits  of,  5 

-  jigs  and  fixtures,  221 

—  jobs,  examples  of,  187 

—  machines,  239,  *240,  *241,  *242, 

*243,    *244,    *245,    *246,    *247, 
*248,  249,  *250,  *251,  252 

-  motion,    *133,    *137,    *147,   *148, 

*149 

—  outfit  on  hand  truck,  *35 

—  portions  for  Thermit  welding  of 

rectangular  sections,  345 

—  rod,  using  the,   137,   *138,  *147, 

*148,  *149 

—  shifts  on  large  work,  213 

—  shop    layout,    295,     *297,    *298, 

*299,  *300 

—  speed  with  a  gas  torch,  61,  68 

—  torch,  Airco-Vulcan,   *91 
,  first,  2 

,  low  pressure,  54,  *55 

,  Messer,  *70,  *71 

— ,Milburn,  *91,  92 

made  by  General  Welding  & 

Equipment  Co.,  *60,  61 

,  positive-pressure,  54,  *55 

,  Prest-O-Lite,    58,    *60 

,  Rego,  64,  *66 

,  Thermalene,    *71,    *72 

—  torches,   54,    *55,   *56,    *57,   *60, 


442 


,  INDEX 


*62,    *66,    *67,    *69,    *70,    *71, 
*72 
Welding  torches,  Davis-Bournonville, 

55,  *56,  *57 
— ,  Imperial,   *62,   63 

,  machine,  *57,  *69,  *70 

,  Oxweld      low-pressure,      *66, 

*67,  *69,  *70 
— ,  types  of,  54,  *55 
-  various  metals,   169,   173 
Welds,  built-up,  *141,  142 


Wheel,  driving,  welding  with  Ther- 
.       mit,  *354 

-  shaft  welds,  *386,  *389 
White  metal  welding,  186 
William     Henry     Mack,      Sternpost 

weld  on  the,  *388 
Willson,  T.  L.,  1 
Wohler,  Frederick,  317 
Wolf,   Linus,   5,  45,   244 
Wrought  iron  welding,  186 


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